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Water is Life, Clean Water Means Health: The Effect of Early-Life
Exposure to City-Wide Water Filtration on Old-Age Male Mortality*†
Hamid Noghanibehambari‡
Jason Fletcher§
Abstract
This study examines the impact of water purification on long-run old-age mortality. We
examine the effects of early-life and childhood exposure to improvements in water quality
due to city-wide water filtration programs in 25 major American cities on later-life old-age
longevity of male individuals. We employ data from Social Security Administration death
records linked with the 1940 census. The difference-in-difference regressions suggest an
improvement in male longevity of about 3.2 months. A series of balancing tests do not
reveal evidence that changes in sociodemographic and socioeconomic characteristics of
individuals confound the estimates. We also implement a full battery of sensitivity analyses
and show that the effect is robust across specifications, subsamples, and functional form
checks. Analyses using 1950-1970 censuses suggest that a portion of the long-term links
can be explained by improvements in individuals’ education and income as a result of
early-life exposure to water filtration. We also show that treated cohorts reveal
improvements in height and cognitive scores during early adulthood.
Keywords: Mortality, Longevity, Public Health, Clean Water, Water Filtration, In-Utero
Exposures, Early-Life Exposures, Historical Data
JEL Codes: I18, J18, N51, N52, O13, Q28
*The authors claim that they have no conflict of interest to report. The authors would like to acknowledge financial
support from NIA grants (R01AG060109, R01AG076830) and the Center for Demography of Health and Aging
(CDHA) at the University of Wisconsin-Madison under NIA core grant P30 AG17266.
† The phrase "Water is life, clean water means health" is inspired by a quote from Audrey Hepburn, who was a
passionate advocate for clean water access.
‡ Corresponding Author, College of Business, Austin Peay State University, Marion St, Clarksville, TN 37040, USA
Email: noghanih@apsu.edu, ORCID ID: https://orcid.org/0000-0001-7868-2900
§La Follette School of Public Affairs, University of Wisconsin-Madison, 1225 Observatory Drive, Madison, WI
53706-1211, USA
Email: jason.fletcher@wisc.edu
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
2
1. Introduction
Contaminated drinking water has been the source of various diseases and a serious threat
to public health for centuries. As of 2019, about 2.2 billion people worldwide still lack access to
safely managed drinking water (WHO 2019). The health impacts of poor water quality are
disproportionate across age distribution, with higher impacts among infants and children. This is
more evident as death rates due to waterborne diseases such as typhoid, cholera, and diarrhea have
been historically higher among infants and children (Armstrong, Conn, and Pinner 1999). In the
US during the early 20th century, there have been substantial improvements in water quality
through a series of state-wide and city-wide campaigns to raise expenditures toward public health
infrastructures. These campaigns were successful in raising the access and quality of water and
contributed to reductions in urban mortality during the first decades of the 20th century (Anderson,
Charles, & Rees, 2022; Beach et al., 2016; Cutler & Miller, 2005; Troesken, 2004) Specifically,
studies suggest that clean water benefits infants’ health more than other age groups (Anderson,
Charles, and Rees 2022). Among many public health interventions, improvements in water
technology, specifically water filtration, have affected infant mortality rates most (Costa 2015).
Studies that use more recent data from developing countries that experience rapid industrialization
suggest the importance of water quality for infants’ health outcomes (Zhang and Xu 2016;
Greenstone and Hanna 2014; Mettetal 2019).
The potential effects of water quality on infants could have long-lasting consequences. A
growing literature suggests that life-cycle outcomes could partly reflect conditions in early-life
(Almond and Currie 2011b; 2011a; Almond, Currie, and Duque 2018; Almond, Currie, and
Herrmann 2012; Aizer et al. 2016; Barker 1997; 1994; 1995; 2004). A strand of this literature
explores the sources of disparate longevity across individuals and documents the significant effects
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
3
of early-life shocks on old-age health and mortality (Bailey et al., 2016; Hayward & Gorman,
2004; Montez et al., 2014; Lindeboom et al., 2010; Scholte et al., 2015; Smith, 2009; Van Den
Berg et al., 2006, 2011). For instance, studies show that in-utero and early-life disease environment
is associated with adulthood education and income and old-age cognitive functioning and
longevity (Blackwell, Hayward, and Crimmins 2001; Crimmins and Finch 2006; Finch and
Crimmins 2004; Moore et al. 2006; Venkataramani 2012; Bleakley 2007; Case and Paxson 2009).
Therefore, the effects of water quality in early life can also be detected in life-cycle outcomes.
However, while the evidence on its short-term effects is abundant, very few studies have explored
the long-term effects, specifically on old-age health and mortality (Grossman and Slusky 2019;
Hafeman et al. 2007; He and Perloff 2016; Jones 2019; Beland and Oloomi 2019). To fill this void
in the literature, this paper examines the effects of water filtration across US cities on old-age
mortality.
Water filtration involves passing water through a series of physical or chemical barriers or
employing other biological mechanisms to remove contaminants, impurities, pollutants,
pathogens, and other harmful microorganisms, resulting in cleaner, safer water. Such filtration and
purification systems are crucial in preventing waterborne diseases, such as cholera, typhoid fever,
and dysentery.
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These diseases are caused by bacteria, viruses, and protozoa in the contaminated
water. While these pathogens are harmful to the whole population, the impacts are considerably
stronger in critical stages of development, especially during in-utero, early life, and childhood
(Kunitz 1984; Condran and Crimmins-Gardner 1978; Beach et al. 2016). Moreover, these diseases
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Several bacterial diseases (e.g., Salmonella infections, Cholera caused by Vibrio cholerae, Typhoid Fever caused by
Salmonella typhi, Dysentery caused by Shigella bacteria, Legionellosis caused by Legionella pneumophila, and certain
strains of E. coli infection), parasitic diseases (e.g., Giardiasis caused by Giardia lamblia, Cryptosporidiosis caused
by Cryptosporidium, and amoebic dysentery caused by Entamoeba histolytica), and viral diseases (e.g., Hepatitis A,
Norovirus infection, and Polio) can be transmitted through contaminated water.
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
4
have spillover impacts on survivors and make them vulnerable to other non-waterborne diseases.
For instance, based on the hypothesis of Mills–Reincke phenomenon, the prevention of typhoid
fever death resulting from water filtration and purification is associated with a threefold reduction
in deaths from other non-waterborne diseases (McGee 1920; Friedrich 1912). Moreover, the low
case-fatality rate of waterborne diseases such as typhoid increases the vulnerability of survivors to
later-life diseases such as tuberculosis, pneumonia, and kidney failure (Ferrie and Troesken 2008).
Therefore, one might expect to detect the benefits of exposure to water filtration during infancy
and childhood for later-life and adulthood outcomes.
This paper employs data from Social Security Administration death records of male
individuals over the years 1975-2005 linked with the full-count 1940 census. We focus on male
individuals because alternative data containing female death records cover a relatively narrower
window of deaths. Furthermore, since women often change their names after marriage and data
linkage between death records and census records is primarily based on name similarities, women
are underrepresented in the linked data. We exploit cross-census linkages to find individual records
in historical full-count censuses 1900-1930 in order to infer their city-of-birth/childhood. We
implement difference-in-difference regressions to compare the longevity of individuals who were
exposed to city-specific water filtration projects across different ages. We show that city-wide
improvements in water quality during in-utero and early-life is associated with about 3.2 months
higher age-at-death during old ages.
The main assumption in our identification strategy is that the longevity of individuals in
cities that implemented water filtration projects would have followed the same path and been
influenced by the same factors in the absence of any water filtration project. We provide empirical
evidence to support the exogeneity of the treatment. We show that the observed effect is not an
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
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artifact of changes in the sociodemographic composition of the final sample due to differential
survival into adulthood, changes in the socioeconomic and sociodemographic composition of cities
following public health reforms, changes in public spending as well as implementation of other
public health interventions, changes in other city-level and state-level policies and reforms,
endogenous merging across censuses and death records, and endogenous fertility. A series of
sensitivity analyses suggest that the effect is robust across a wide range of alternative
specifications, functional forms, and subsamples.
To explore mechanism channels, we use census data for the years 1950-1970, a period
when cohorts under study are experiencing their adulthood years. We show that exposure to water
quality improvements in the year-of-birth is associated with higher schooling, higher income, and
increased socioeconomic scores. Several studies document the association between
education/income profile and later-life longevity (Chetty et al., 2016; Cristia, 2009; Cutler et al.,
2006; Fletcher et al., 2021; Fletcher, 2015; Kinge et al., 2019; Lleras-Muney, 2022). Therefore,
we argue that increases in education and improvements in labor market outcomes could be
potential mechanism channels.
This paper contributes to two strands of literature. First, to our knowledge, this is the first
study to examine the long-run mortality effects of water quality in early-life. While several studies
document the relevance of in-utero and early-life water quality exposure on education and labor
market outcomes, no study has explored its effects on old-age health and mortality (Beach et al.,
2016; Smith et al., 2012; Zaveri et al., 2019; Zhang & Xu, 2016). More specifically, this study is
the first to examine the long-term effects of water quality improvements in the US’s first decades
of the 20th century on later-life health outcomes. Studies that examine health effects of public
health interventions during this era have focused mostly on short-run outcomes (Anderson,
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
6
Charles, and Rees 2022; Anderson et al. 2022; 2019; D. Cutler and Miller 2005). Improving
drinking water quality reduces the disease burden of early-life environments. Therefore, our study
also evaluates the impact of reducing early-life disease burden on later-life health. Hence, the
second contribution of our paper is to add to the growing literature on the relevance of early-life
disease environment and later-life mortality (Case and Paxson 2009; Case, Fertig, and Paxson
2005; Bleakley 2007; Crimmins and Finch 2006; Almond, Currie, and Herrmann 2012; Cormack,
Lazuka, and Quaranta 2024).
The rest of the paper is organized as follows. Section 2 reviews the literature. Section 3
introduces data sources and sample selections. Section 4 discusses the econometric method.
Section 5 reviews the main results. Section 6 explores potential mechanism channels. Finally, we
depart some concluding remarks in section 7.
2. A Brief Literature Review
Several studies document the health benefits of public health infrastructures in American
cities during the early decades of the 20th century. Cutler & Miller (2005) employ data from 13
major American cities and explore the role of improvements in clean water technologies in
reducing urban mortality rates. They find significant reductions in total mortality rates. Further,
they show that infant mortality drops by about 35% in the years following water disinfection.
Anderson, Charles, & Rees (2022) revisit their analysis and make some corrections to their data
caused by transcription errors. Their reevaluation suggests smaller but significant impacts of water
filtration. They document that post-water filtration infant mortality drops by about 11%. Although
they also explore the impacts of other public health interventions, including water projects, water
chlorination, water filtration, and sewage treatment, they fail to find statistically significant effects
of any of these interventions. Anderson et al. (2019) examine the effect of tuberculosis movements
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
7
in the US between 1900-1917 on TB mortality rates. They find modest and mostly insignificant
effects of various anti-TB measures on mortality. However, they show that establishing state-run
sanatoriums resulted in about 4 percent reductions in pulmonary TB mortality. Anderson, Charles,
McKelligott, et al. (2022) explore the effect of milk inspections in major American cities during
1880-1910 on infants’ and children’s mortality and find small and insignificant effects.
A strand of research employs more recent data and explores the association between water
quality and infants’ and children’s health outcomes (Apergis et al., 2019; Currie et al., 2017;
Greenstone & Hanna, 2014; Hafeman et al., 2007; He & Perloff, 2016; Hill & Ma, 2017). For
instance, Clay et al. (2014) examine the effects of exposure to lead in drinking water across cities
in the US between 1900-1920. They exploit the fact that lead is more likely to leach into drinking
water if the water is more acidic. They document that going from the city with high exposure to
the city with low exposure in their sample is associated with a 7-33 percent reduction in infant
mortality rates.
Grossman & Slusky (2019) examine the impact of the Flint water crisis, in which the city
of Flint, Michigan, changed its water supply resulting in sharp increases of contaminants in the
water supply, on fertility and birth outcomes. They find that rises in drinking water contaminants,
including lead, resulted in a 12 percent decrease in fertility rate and a 5.4 percent reduction in birth
weight. Currie et al. (2013) examine the impact of water quality on birth outcomes using data from
New Jersey between 1997-2007. They compare birth outcomes of infants from the same mother
who were exposed to differential contaminations in drinking water. They find negative and
significant effects on birth weight and the gestational length of infants of low-educated mothers.
Brainerd & Menon (2014) investigate the effect of water pollution due to seasonal changes in
fertilizer agrichemical use on infants’ and children’s health outcomes in India. They show that
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
8
children exposed to higher levels of agricultural water pollution exposure reveal higher mortality
rates and lower height and weight-for-age scores. Hill & Ma (2022) and Hill (2018) provide
evidence that shale gas development during the recent fracking boom in the US resulted in higher
water pollution and negative impacts on infants’ health outcomes. Jones (2019) examines the
impact of microcystin in drinking water, a potent toxin produced by cyanobacteria in freshwater
algal blooms, on infants’ health outcomes. He uses data from Michigan and exploits a one-time
municipal attempt to improve water quality and remove algae. He finds that the intervention
increased to 17 grams in birth weight and 3.2 days additional gestational age.
Therefore, one expects to observe positive impacts of improvements in water quality on
infants’ health. Healthier infants are more likely to experience a healthier childhood, develop more
cognitive and noncognitive skills, attain higher levels of human capital, reveal better labor market
outcomes, and generally have a healthier adulthood (Behrman & Rosenzweig, 2004; Black et al.,
2007; Cook & Fletcher, 2015; Fletcher, 2011; Maruyama & Heinesen, 2020; Royer, 2009; Shenkin
et al., 2009). A narrow strand of research examines the direct link between in-utero and early-life
exposure to a change in water quality and later-life outcomes (Smith et al., 2006, 2012; Zaveri et
al., 2019). For instance, Beach et al. (2016) argue that water purification technologies significantly
reduced typhoid mortality rates. They proxy water quality with city-level typhoid mortality for the
period 1900-1940 and examine the impacts of improvements in water quality in early-life on
adulthood education and earnings. They find that water improvements resulted in an increase of
about 9 percent higher adulthood income and 0.7 years additional years of schooling. Zhang & Xu
(2016) examine the impact of a major water treatment program in rural China. They find that those
who benefited from the program in early-life attain roughly 1 additional year of schooling during
adulthood.
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Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
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3. Data and Sample
The primary data source of this study comes from Death Master Files (DMF) of Social
Security Administration death records extracted from the Censoc Project (Goldstein et al. 2021;
Breen, Osborne, and Goldstein 2023; Breen and Osborne 2022). DMF data covers deaths that
occurred among male individuals born between 1975 and 2005.
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It contains information on dates
of birth, death, limited demographic characteristics, and an identifier to link the individual with
the full-count 1940 census. DMF data has two advantages that make it superior to alternative data
sources in examining long-term associations. First, the raw data contains millions of observations,
allowing for various types of heterogeneity analyses. Second, the data contains all familial and
geographic information available in the 1940 census. Specifically, we have information on the
below-state place of residence in both 1935 and 1940, as reported in the 1940 census. Moreover,
the existence of cross-census linking rules allow researchers to link the full-count 1940 census to
historical censuses which enables them to observe place-of-residence of individuals in earlier
decades. We merge the DMF data with the 1940 census extracted from Ruggles et al. (2020).
We use city-level water filtration project data from Anderson, Charles, & Rees (2022). It
provides a city-by-year panel of 25 major cities between 1900-1940 and reports whether a city has
a water filtration system each year. Figure 1 shows the geographic distribution of cities in the final
sample and the year each city implemented water filtration. Error! Reference source not found.
provides a list of these cities with the year of water filtration in each city.
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The DMF data reports deaths to male individuals only. We use the Berkeley Unified Numident Mortality Database
(BUNMD) to examine the effects across both genders. The disadvantage of BUNMD data is that its death coverage
is more comprehensive post-1988 years and that it is not linked to the 1940 census. Hence, we implement the main
analysis of the paper using DMF data. In Error! Reference source not found., we show that using BUNMD data we
observe almost identical coefficients to those of the main results if restrict the sample to male individuals only.
However, among female individuals, the coefficients are considerably smaller in magnitude and statistically
insignificant.
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Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
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Since this study focuses on assessing early-life exposures, we need to assign city-level
water filtration status based on individuals’ year-of-birth and city-of-birth/childhood. However,
the 1940 census does not report the city-of-birth/childhood. One idea is to use the city-of-residence
in 1935 and 1940 as a proxy for place-of-birth. However, individuals may migrate from their
birthplace, and this migration could be a response to city-level improvements in public health,
hence being endogenous. To mitigate this issue and infer city-of-birth/childhood, we start with
DMF-census-linked data and merge the records with historical censuses 1900-1930 using cross-
census linkage datasets extracted from Abramitzky et al. (2020). We then use the geographic
information provided by the census in which a person appears for the first time in any census as
the place of birth/childhood.
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We then merge the DMF-census data with the water filtration data
based on birth/childhood-city and birth-year.
8
In our regressions, we also control for a series of city-by-year covariates. These covariates
are constructed using full-count decennial censuses 1900-1940 and linearly interpolated for inter-
decennial years. Section 6 also uses censuses from 1950-1970 to explore potential pathways. These
census data are extracted from Ruggles et al. (2020). Finally, in section 5.3, we employ natality
and mortality data at the city level extracted from Bailey, Clay, et al. (2016).
Our sample consists of a relatively long birth window (i.e., 41 years) and a relatively
limited death window (i.e., 31 years). One concern in our sample selection is that our method of
comparison between early versus late filtration adoption could reflect the longevity differences
7
To the extent that migration is correlated with childhood exposure to water filtration, measurement errors induced
by migration in city of birth/childhood assignment may confound our estimates. In Error! Reference source not
found., we argue that although between 20-40% of the linked samples (from the full count 1940 census to 1910-1930
census) moved across cities, such migration patterns do not correlate with exposure to water filtration after accounting
for fixed effects and covariates.
8
Error! Reference source not found. discusses cross-census linking procedure and steps of sample construction in
more detail.
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Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
11
between earlier cohorts versus later cohorts. This problem is more evident given the sharp rises in
life expectancy at birth for these cohorts (Smith & Bradshaw, 2006). To mitigate this issue, we
restrict cohorts to those born 15 years before and after the city-specific year of water filtration.
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The final sample includes 338,758 observations born between 1900-1940 and who died
between 1975-2005. Summary statistics of the final sample are reported in Table 1. The average
age-at-death is 867.2 months or 72.3 years but it varies between 35-104 years.
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Roughly 98
percent of the observations are white. This overrepresentation of whites in the final sample results
from a higher match rate among whites both in the DMF-1940-census match and in linking
historical censuses. In section 5.3, we empirically test whether the observed match rules are
endogenous, i.e., they are correlated with city-level water filtration. Moreover, Breen & Osborne
(2022) argue that while certain groups are underrepresented in the Censoc-linked death records,
they represent their original population of 1940 records in terms of socioeconomic and education.
About 90 percent of mothers and fathers are literate. The parental information is also extracted
from the earliest census each individual appears. Therefore, they reveal parental covariates during
individuals’ birth/childhood. Roughly 95 percent of fathers are active in the labor force at the time
of the 1940 census enumeration. Our primary independent variable is the share of childhood years
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In Error! Reference source not found., we argue that this selection is not critical for the main findings. Removing
this restriction or making a stricter balancing window of selection around water filtration reforms only slightly changes
the coefficient size.
10
We do not restrict the sample based on age at death. One concern is that individuals who were born earlier in the
sample and were exposed to earlier filtration reforms must have lived into much older ages to be in the final sample
than those later cohorts. Moreover, the longevity of earlier cohorts for inclusion in the final sample is beyond the life
expectancy of cohorts in the early 20th century. Therefore, these cohorts could possibly contain quiet different
characteristics than the later cohorts to have lived beyond life expectancy of their cohorts. Such differential longevity
of earlier versus later cohorts might bring causes of concern related to endogenous survival. In Error! Reference
source not found., we restrict the sample to individuals survived up to ages 50, 55, 60, 65, and 70 and replicate the
main results. We observe coefficients that are about 30% smaller than the main results. This fact implies two scenarios.
One, the benefits of filtration appear to be larger for younger ages at death and that expanding death window to cover
deaths prior to 1975 might increase coefficient sizes. Second, possible survival selection of earlier cohorts might bias
coefficients downward and that the main results underestimate the true effects.
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Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
12
(ages 0-15) that the individual is exposed to water filtration. The average share of exposure is 0.16
with a standard deviation of 0.36.
4. Econometric Method
To operationalize the long-run effects of water filtration on mortality, we implement a
difference-in-difference framework to compare the age-at-death of individuals who were exposed
to the adoption of the water filtration system to those in cities without a filtration system across
different ages during their childhood. In other words, we examine the impacts across different ages
at exposure. Specifically, we implement regressions of the following forms:
(1)
Where is age-at-death (in months) of individual who was born in city in census region
and belonged to birth-year . is a unit function that equals one if the inside argument is true.
represents city-specific year of water filtration. Therefore, the parameters represent impacts
across various age-at-exposure . For instance, is the coefficient of exposure for cohorts who
turn age 5 at the time of water filtration. Similarly, is the coefficient of exposure of cohorts who
are born 5 years post-waterwork, hence a full in-utero and childhood exposure. We eliminate the
coefficient of 13-15-year-old individuals (i.e., =[-15,-13]) to compare all coefficients to the values
of the oldest cohorts in our sample.
In matrix , we include individual and family covariates, including indicators of race,
ethnicity, maternal literacy, paternal literacy, and paternal occupational income score. In , we
include city-level controls including share of married, labor force participation rate, share of people
in different occupations, share of homeowners, share of children, and average socioeconomic
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Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
13
score. The parameter represents city fixed effects that account for time-invariant city-level
confounders in longevity. Therefore, we rely on cross-cohort differences post-versus-pre water
filtration to eliminate the unobserved heterogeneity across cities. The parameter represents birth-
cohort by birth-region fixed effects to absorb unobserved temporal heterogeneity across cohorts
that are specific to each census region. Finally, is a disturbance term. We cluster standard errors
at the city level. Since the final sample includes only 25 cities, we have very few clusters to rely
on inference based on city-level clustering. Therefore, in visual representations of equation 1, we
illustrate confidence intervals extracted from the wild bootstrap procedure.
We further examine the impacts in a difference-in-difference framework and assign the
exposure measure based on the share of childhood years (up to age 15) that an individual was
exposed to water filtration. Specifically, we implement regressions of the following forms:
(2)
In this formulation, the variable is the share of childhood between ages 0-15 that the
individual was exposed to water filtration. For instance, Baltimore, MD initiated water filtration
in 1915. An individual born in 1910 is potentially exposed to water filtration for ages 6-onward.
Hence, the average share of exposure is 0.6.
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Therefore, is the parameter of interest that
captures the association between full exposure to water filtration (versus no exposure) and old-age
longevity. All other parameters are similar to those of equation 1. In all regressions, we report P-
values based on wild bootstrap procedures.
11
Recall that we limit the sample to those born 15 years pre- and post-waterwork. In Error! Reference source not
found., we show the results for other threshold ages. Specifically, we assign exposure measure up to age 1, 5, 10, and
14. Since all these age groups are treated in the final sample, as we limit exposure ages, we expect to observe smaller
coefficients as those ages join the reference group.
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14
5. Results
5.1. Age-at-Exposure Analysis
The main results of equation 1 are reported in the top panel of Figure 2. Compared to
cohorts 13-15 years old at the time of water filtration, we observe very small changes for
individuals 11-12 years old. For cohorts between ages 5-10, we observe a positive average effect
that is small in magnitude. The effects start to rise for those 3-4 years old and younger. For
instance, the coefficients imply an increase of 0.8, 3, and 1.5 months of additional longevity for
age of exposure of [5,6], [3,4], and [1,2], respectively. For exposure during year of birth and
between 1-7 years prior to birth, the coefficients suggest increases in longevity in the range of 1.9
– 2.5. Overall, four out of seven coefficients for the age group of 3-4-and-younger are statistically
significant at the 5 percent.
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Difference-in-Difference Bias. The literature suggests that OLS-produced difference-in-
difference estimates in a staggered adoption setting where different units receive treatments in
different periods could produce biased estimates (Callaway and Sant’Anna 2021; Borusyak,
Jaravel, and Spiess 2021; Sun and Abraham 2021; Goodman-Bacon 2021). To explore this
potential bias, we implement an alternative difference-in-difference method developed by Sun &
Abraham (2021) and replicate the regressions of equation 1. The results are depicted in the bottom
panel of Figure 2. Compared with the OLS estimations of the top panel, we observe a very similar
pattern in estimated effects, suggesting little bias in the OLS estimates.
12
In Error! Reference source not found., we group different ages at exposure to observe and compare coefficient
sizes across different ages. Specifically, we examine exposure during in utero and age 0, ages 1-4, and ages 5-9. We
find a monotonic pattern: the earlier the exposure, the larger the coefficient. For instance, for in utero and early-life,
exposure is associated with 3.3 months higher longevity while for exposure during ages 1-4 the coefficient implies a
2.6-month rise in longevity.
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15
5.2. Main Results
The main results of equation 2 for the cumulative childhood exposure are reported in Table
2. We start with a parsimonious model that only includes city fixed effects, birth-year fixed effects,
and individual and family controls (column 1). Then, we add city controls in column 2 and birth-
region-by-birth-year fixed effects in column 3. The estimated effects are quite stable across
specifications. Based on the fully parametrized specification of column 3, exposure to filtered
water throughout childhood is associated with about 3.2 months higher longevity.
This finding is in line with a narrow literature that shows removing contaminants in
drinking water, e.g., arsenic, during in-utero and early-life could reduce mortality in young adults
(Smith et al., 2006, 2012). This is also consistent with studies that suggest improvements in early-
life water quality increase later-life human capital (Zhang and Xu 2016; Beach et al. 2016).
We can compare this effect with the impacts of other early-life exposures to gauge its
economic magnitude. Aizer et al. (2016) examine the impacts of the Mothers’ Pension (MP)
program, a cash transfer needs-based program to help poor families, on later-life education and
longevity. They find that MP receipt during childhood is associated with 0.6 years of more
schooling and almost 1 year of additional longevity. MP transfers accounted for about 12-25
percent of family income and lasted for three years, resulting in a cumulated income shock of about
50 percent of family income. Therefore, the intent-to-treat effect of Table 2 is equivalent to an
increase of 13.3 percent in family income. Halpern-Manners et al. (2020) employ twin fixed effect
strategy and explore the effect of education on longevity. They find that an increase of 1 year of
schooling is associated with about 4 months higher longevity. Therefore, our estimated effect is
equivalent to about 0.8 additional years of schooling. Noghanibehambari & Fletcher (2023b)
explore the impact of in-utero exposure to state-level and federal alcohol prohibition during the
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16
early decades of the 20th century on old-age longevity. They find that prohibition is associated with
a treatment-on-treated increase of 1.7 years in longevity. The estimated impact of Table 2 suggests
that unfiltered water has at least about 16 percent of the effect of alcohol consumption during
pregnancy. Fletcher & Noghanibehambari (2024) examine the in-utero and early-life exposure to
agrichemical pesticide exposure on old-age longevity. They use the emergence of cyclical cicadas
in eastern states that raises the pesticide use in tree croplands as a natural experiment. They employ
DMF data and show that exposed cohorts reveal 2.2 months lower longevity. They argue that
contaminating drinking water is a likely channel of exposure of infants and mothers to pesticide
use. Their estimated effect is about 69 percent of the benefit of water filtration in the current study.
5.3. Endogeneity Concerns
This section discusses several potential sources of endogeneity and selection concerns. We
list these concerns below and attempt to empirically test them using available data.
Balancing Tests. One concern is that the final sample is unbalanced and represents certain
sociodemographic populations more than others. If this over/under-representation is correlated
with water filtration even after controlling for fixed effects and covariates, then the regressions
produce biased estimates. For instance, assume that following the public health improvements that
resulted in water filtration, cities observe a sharp inflow of migrants from neighboring cities and
counties. Also, assume that there are more whites and people of better socioeconomic conditions
among these migrants. In this case, the regressions overstate the true effects and capture the higher
longevity of these subpopulations of migrants rather than the effect of water filtration. Another
source of an unbalanced sample is differential mortality and survival into adulthood and old age.
If childhood and middle age mortality is affected by early-life water quality and the effects vary
by sociodemographic characteristics, then the observed effects on longevity could reflect the
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17
differential mortality patterns of survivors rather than the direct impact of water quality. We can
directly examine these sources of endogeneity by implementing a series of balancing tests. In so
doing, we use individual and family characteristics as the outcomes and implement regressions of
equation 1, conditional on city and region-by-cohort fixed effects. We then depict the coefficients
dummies for each outcome in different panels of Figure 3 through Figure 5. To facilitate
comparison across panels and figures, we standardize each outcome with respect to the mean and
standard deviation of the sample. We do not observe a discernible effect on the likelihood of being
white, black, or Hispanic across ages of exposure to the water filtration reforms (top-left, top-right,
and bottom-left panels of Figure 3). The coefficients are economically small and statistically
insignificant at 95 percent level.
However, we observe negative and significant coefficients for the outcome of mother
literate for younger children (bottom-right panel of Figure 3). Since mother education is shown to
have a positive impact on infants’ and children’s health, these reductions suggest that our results
may underestimate the true effects (Lundborg, Nilsson, and Rooth 2014; Huebener 2020; 2019;
Noghanibehambari, Salari, and Tavassoli 2022).
We do not observe any discernible change across ages following the reform for mother
labor force status, father literacy, and missing indicators of parental literacy (Figure 4). We also
observe no cross-age trend in the father’s socioeconomic and occupational income scores (top-
right and bottom-left panels of Figure 5, respectively).
13
13
We further examine potential changes in fertility following water filtration. These results are discussed in Error!
Reference source not found.. Although consistent with prior research in this area we find reductions in infant
mortality rates, we do not observe significant changes in birth rate (Anderson, Charles, & Rees, 2022; Cutler & Miller,
2005).
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A similar concern relates to the fact that water filtration may be preceded by other state-
level policy changes or city-level socioeconomic and sociodemographic changes. Thus, to the
extent that such place-specific policy evolution and compositional changes correlate with
longevity, the impacts might pick up on these confounders rather than water filtration. In Error!
Reference source not found., we implement event studies to examine the evolution of state-level
and city-level outcomes in different years relative to water filtration years, conditional on city and
region-by-year fixed effects. The evidence does not provide empirical support for this concern.
Specifically, we do not observe any association between the water filtration and prohibition
movement, suffrage movement, tax policies, birth registration laws, child labor laws, compulsory
attendance laws, sociodemographic composition, and a battery of socioeconomic outcomes.
14
Similarly, one might argue that water filtration projects are one step out a larger set of
staggered piecemeal development plans that expand the general provision of public goods. In that
case, the effects pick up on the benefits of other public projects and social spending. In Error!
Reference source not found., we empirically investigate such concerns, and, through a series of
event studies, show that water filtration projects do not correlate with spending on public
education, per capita doctors as a measure of healthcare access, water chlorination projects, and
several other public health intervention projects.
Endogenous Merging with Censuses. Selection from the original population to the final
sample caused by data linking may generate bias in our estimations if the selection procedure is
correlated with water filtration projects (see section 3 and Error! Reference source not found.).
To examine this source of selection-induced endogeneity, we assess the association between
14
The policies mentioned here and explored in Error! Reference source not found. are documented to influence
later-life mortality and longevity (Lleras-Muney 2005; Noghanibehambari and Fletcher 2023a; Noghanibehambari
and Noghani 2023; Noghanibehambari and Fletcher 2023b).
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19
successful survival from the original population to the final sample with the water filtration
exposure measure. In so doing, we start with the universe of cohorts born between 1900-1940 and
who reside in the final sample’s cities. We merge this population with those in the final sample
and generate a successful merger dummy if the merging is successful. We then implement
regressions that include city and cohort-by-region fixed effects, similar to equation 2. The results
are reported in Table 3. We show the estimated associations between successful merger and water
filtration for the full sample, sample of whites, and sample of nonwhites in columns 1-3,
respectively. The coefficients suggest insignificant associations. Moreover, the magnitude of the
effects is small. For instance, exposure to water filtration is associated with an insignificant 2.6
basis-points increase in the probability of merging, equivalent to about a 0.8 percent change from
the outcome mean. These results do not provide evidence for the endogeneity caused by cross-
census and DMF-census linking and selection.
5.4. Robustness Checks
In Table 4, we explore the sensitivity of the results to alternative model specifications.
Column 1 replicates the results of column 3 of Table 2 to provide a benchmark comparison. All
other columns include all covariates and fixed effects used in column 1. In column 2, we interact
birth-state by 1940-state fixed effects to control for the influence of early- adulthood cross-state
migration on the water-longevity relationship. The estimated effect is quite similar to the main
results.
In columns 3-4, we interact city fixed effects with individual and family dummies. Thus,
we allow for time-invariant unobserved factors of each city to have a differential impact on health
and longevity across people of different sociodemographic and socioeconomic backgrounds. The
estimated effects are comparable to that of column 1.
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Studies suggest that the season of birth is associated with infants’ health and later-life
mortality (Doblhammer and Vaupel 2001; Currie and Schwandt 2013). Moreover, several causes
of death reveal a seasonality pattern (Seretakis et al. 1997; Falagas et al. 2009). To account for
seasonality-related confounders, we add birth-month and death-month fixed effects to the
regressions. The result, reported in column 5, is almost identical to that of column 1.
In column 6, we add a wide range of additional city-level controls, including share of
people in different demographic groups, share of people in different age groups, average
socioeconomic score, female labor force participation rate, male labor force participation rate,
female literacy rate, male literacy rate, and population. The estimated effect becomes only slightly
smaller than the main results and remains statistically significant.
In column 7, we implement an alternative standard error correction method. Instead of
clustering, we use Huber-White robust standard error. The estimated effect remains statistically
significant at 95% level.
Another concern is regarding the functional form of the regressions. In column 8, we
replace the outcome with the log of age-at-death, hence estimating a semi-log specification. We
observe an effect of a 0.38 percent rise in longevity. This is very similar to the 0.37 percent rise
with respect to the outcome mean, implied by column 1. In column 9, we replace the outcome with
a dummy variable that equals one if the individual’s age-at-death is more than 75 years. Early-life
water filtration is associated with a 1.5 percentage-point rise in the probability of living beyond 75
years, off a mean of 0.38.
The main regressions of the paper do not incorporate any weighting method. In column 10,
we assign higher weights to more populated cities by weighting the regressions using the average
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city population. The estimated effect increases by roughly 19% and remains statistically
significant.
Several studies suggest the long-term effects of early-life exposure to the Spanish Flu of
1918-1919 (Almond & Mazumder, 2005; Cook et al., 2019; Fletcher, 2018a, 2018b; Myrskylä et
al., 2013). In column 11, we remove cohorts born between 1918-1919 who were likely affected by
the pandemic. The estimated effect is quite similar to column 1.
The Great Depression induced unprecedented economic hardship among families that
could affect the children’s long-term outcomes (Cutler et al., 2007; Noghanibehambari et al., 2024;
Van Den Berg et al., 2006, 2009). Moreover, studies point to the benefits of New Deal relief
programs during this period for later-life outcomes (Noghanibehambari and Engelman 2022). Both
economic conditions and social spending could confound our estimates if they are correlated with
water filtration exposure. In column 12, we remove cohorts born between 1930-1940 who were
probably impacted by the Great Depression and New Deal social spending. The estimated effect
is quite similar to that of column 1.
6. Mechanisms
Improvements in health accumulation during infancy and childhood could lead to higher
longevity through several mediatory channels, including better human capital accumulation, better
mental health, better physical health, lower obesity, higher probability of family formation, better
spousal attributes, and higher socioeconomic index (Benítez-Silva & Ni, 2008; Cutler et al., 2006;
Diener & Chan, 2011; Gardner & Oswald, 2004; Lleras-Muney et al., 2022; Lleras-Muney &
Moreau, 2022; Noghanibehambari & Fletcher, 2023b, 2023c, 2023d; Preston, 2005; Van Den Berg
et al., 2015). In this section, we examine two important channels, education and socioeconomic
measures during adulthood. Since many cohorts have not yet completed their education in the 1940
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census or entered the labor force, we turn to decennial censuses 1950-1970. We use information
about the city of residence in these censuses to proxy for city-of-birth. We restrict the sample to
male individuals born between 1900-1940 aged 25-55 and merge the data by water filtration
database based on census-city and year-of-birth. We assess the association between water filtration
and education/socioeconomic outcomes by implementing regressions that include individual
covariates, census year fixed effects, birth-year-by-birth-region fixed effects, and city fixed effects.
The results are reported in Table 5. Early-life and childhood water exposure are associated with
roughly 3.5 additional months of schooling (column 1). This effect is similar to the OLS findings
of Beach et al. (2016), who examine the effect of water purification in early-life on later-life
education. Water filtration also leads to about 3.7 percentage-points reductions in the likelihood
of less than high school education, off a mean of 0.16 (column 2).
Water quality exposure in early-life is also linked with socioeconomic measures. Exposure
to water filtration during childhood results in a 1.8-unit increase in the socioeconomic index,
equivalent to a 4.8 percent rise from the mean of the outcomes (column 4). We also observe
positive impacts on family income although the point estimates are noisy and limit interpretation
(columns 5-6).
If improvements in human capital and measures of socioeconomic status are mechanism
channels, then one would expect that these pathways follow similar heterogeneous variations as
those of longevity. In Error! Reference source not found., we provide evidence of significant
and sizable reductions in infant mortality following water filtration. If such improvements are the
results of water filtration and improvements in initial health capital, we may observe larger impacts
on longevity outcomes in areas with higher initial infant mortality rates. In Error! Reference
source not found., we examine this source of heterogeneity and show that the effects are
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considerably larger for the subsample of high infant mortality rate cities. Moreover, we show that
the effects on schooling and socioeconomic index are primarily driven by the high infant mortality
subsample, supporting the role of human capital as mechanism channels between exposure to
water filtration and later life mortality.
15
The next question is to what extent improvements in these outcomes can explain the link
between water filtration and longevity. Chetty et al. (2016) examine the association between
household income and individual longevity in the US between 2001-2014 using individual tax
returns linked to the mortality database. They find that for each 5-percentile increase in income,
longevity increases by 0.7-0.9 years. For a household in the median of the sample, this means an
increase of about $40K (in 2020 dollars). Therefore, an increase of $2,603 (induced by water
filtration, column 5 of Table 5) is associated with about 0.62 months higher longevity. This is
about 20 percent of the reduced-form effect of Table 2.
Halpern-Manners et al. (2020) and Cutler & Lleras-Muney (2006) estimate that an increase
of 1 year in schooling is associated with 0.34 and 0.6 years higher longevity. Combining these
estimates with the estimated effect of column 1 of Table 5, one can deduce that the water-filtration-
induced rise in schooling leads to 1.2-2.1 months higher longevity. These effects are equivalent to
15
If the population of infants that survived as a result of water filtration is weaker (who would have died for their
weakness of other reasons in the absence of water filtration), then the overall benefits on longevity underestimate the
true effects. On the other hand, if water filtration brings health benefits and the results illustrate the improvements in
infants’ health capital, then the observed impacts on infant mortality are indeed the primary mechanism channel. We
can do a back-of-an-envelope calculation to examine this. Using Social Security Administration cohort life tables, we
estimate that the difference between post-infancy life expectancy and life expectancy at birth increased by about 4.5
years between the years 1900-1940 (SSA 2020). Based on aggregate vital statistics death records, infant mortality
rates decreased from around 150 to 47 infant deaths per 100K births (CDC 2015). The results of Error! Reference
source not found. implies a reduction of about 6 infants per 100K. Assuming that the difference in life expectancy at
age 1 and 0 can be solely attributed to reductions in infant mortality, the reduction of 6 infants per 100K imply roughly
3 months increases in life expectancy, a number that is quite similar to our main results.
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about 37-65 percent of the effect of column 3 of Table 2. Therefore, improvements in
education/income can explain about 20-65 percent of the observed long-term links.
To complement the mechanism channel analysis, we employ World War II enlistment data
linked with the 1940 census and DMF, extracted from Goldstein et al. (2021). This data is a subset
of DMF data in our main analysis for individuals who were enlisted for World War II. We explore
the effects on two measures of human capital and health capital. First, we focus on the Army
General Classification Test (AGCT) score. The AGCT was designed to capture the learning and
intellectual abilities of enlistees during World War II in order to assign them to different military
tasks and jobs (Potter, Helms, and Plassman 2008). Second, we explore the effects on height as
reported by enlistment enumerators. Height is an indicator of general health and is correlated with
other economic and health outcomes (Deaton and Arora 2009; Bozzoli, Deaton, and Quintana-
Domeque 2009; Deaton 2007). Specifically, some studies link height to old-age health and
longevity (Jousilahti et al. 2000; Spijker, Cámara, and Blanes 2012; Wilson 2019). We implement
the same sample construction and empirical method as the main results. The results are reported
in columns 7-8 of Table 5. We find a positive link between childhood exposure to water filtration
and AGCT score as well as height. Full exposure to water filtration during childhood is associated
with a 1.5% higher AGCT score and 1.7% increase in height. The wild bootstrap p-values for the
estimated coefficients of AGCT score and height are 0.17 and 0.15, respectively.
7. Conclusion
In the early 20th century, state and local authorities initiated a series of improvements in
public health infrastructure, including drinking water filtration and purification. In later decades,
many state and federal laws, including the Safe Drinking Water Act, Water Pollution Control Act,
and Clean Water Act, attempted to elevate drinking water quality further. Although there have
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25
been substantial improvements in the quality of drinking water, there remain communities with
access to unsafe water (Mueller and Gasteyer 2021). There are also instances of temporary water
pollution with considerable negative health consequences (Grossman and Slusky 2019; Jones
2019). The situation is far worse in the rest of the world, specifically in poorer countries. About 1
in 4 people lack safely managed drinking water at home (WHO 2019). According to UNICEF
estimates, billions of people will lose access to safely managed drinking water by 2030 (UNICEF
2021). Therefore, it is important and policy-relevant to document the short-run and long-run effects
of water quality on human health outcomes.
This paper explored the long-run effects of in-utero and early-life exposure to water
filtration on old-age longevity. We exploited city-wide public health efforts to initiate a water
filtering system to purify water across 25 major American cities in the early 20th century. Our
results suggested a benefit of 3.2 months of additional longevity. We implemented a wide array of
tests to argue against endogeneity issues. We provided empirical evidence that changes in
sociodemographic and socioeconomic characteristics do not confound the estimates. We found no
evidence that these public health interventions coincide with any other city, county, or state-level
policy changes. Finally, we showed that the results are robust to a wide array of specification
checks, subsamples, and functional form checks.
Life expectancy at birth among male Americans increased from 46.3 to 60.8 years between
1900-1940, an increase of roughly 174 months of additional longevity. Based on our estimated
effect of Table 2, exposure to cleaner water as a result of water filtration can account for about 2
percent of the overall improvements in longevity for cohorts born between 1900-1940.
In our final sample, about 15.6% of observations are fully exposed to water filtration during
their childhood. Using the intent-to-treat estimate of the main results combined with the number
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26
of fully exposed individuals in the final sample, one can calculate 14.1 thousand life years gained
due to childhood exposure to improvements in water quality as a result of water filtration.
16
Further, we can monetize this number using the Value of Statistical Life (VSL) estimates. Studies
suggest a VSL of about $10 million for the case of the United States (Kniesner and Viscusi 2019;
Viscusi 2018). Given the average longevity in the final sample of 72.3 years, one can roughly
calculate an annual VSL of $138.3 thousand. Therefore, the overall improvement in longevity of
the exposed cohorts in the final sample due to childhood exposure to water filtration is equivalent
to roughly $2 billion.
16
This is calculated using the number of fully exposed individuals in the final sample (15.6% of 338,758
observations), multiplying by the estimated effect of 3.2 months of additional longevity from Table 2, and
converting this value into years:
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27
References
Abramitzky, Ran, Leah Boustan, and Myera Rashid. 2020. “Census Linking Project: Version 1.0
[Dataset].” https://doi.org/https://censuslinkingproject.org.
Acemoglu, Daron, and Joshua Angrist. 2000. “How Large Are Human-Capital Externalities?
Evidence from Compulsory Schooling Laws.” NBER Macroeconomics Annual 15 (June):9–
59. https://doi.org/10.1086/654403.
Aizer, Anna, Shari Eli, Joseph Ferrie, and Adriana Lleras Muney. 2016. “The Long-Run Impact
of Cash Transfers to Poor Families.” American Economic Review 106 (4): 935–71.
https://doi.org/10.1257/AER.20140529.
Almond, Douglas, and Janet Currie. 2011a. Human Capital Development before Age Five.
Handbook of Labor Economics. Vol. 4. Elsevier. https://doi.org/10.1016/S0169-
7218(11)02413-0.
———. 2011b. “Killing Me Softly: The Fetal Origins Hypothesis.” Journal of Economic
Perspectives 25 (3): 153–72. https://doi.org/10.1257/JEP.25.3.153.
Almond, Douglas, Janet Currie, and Valentina Duque. 2018. “Childhood Circumstances and
Adult Outcomes: Act II.” Journal of Economic Literature 56 (4): 1360–1446.
Almond, Douglas, Janet Currie, and Mariesa Herrmann. 2012. “From Infant to Mother: Early
Disease Environment and Future Maternal Health.” Labour Economics 19 (4): 475–83.
https://doi.org/10.1016/J.LABECO.2012.05.015.
Almond, Douglas, and Bhashkar Mazumder. 2005. “The 1918 Influenza Pandemic and
Subsequent Health Outcomes: {An} Analysis of {SIPP} Data.” American Economic Review
95 (2): 258–62.
Anderson, D. Mark, Kerwin Kofi Charles, Michael McKelligott, and Daniel I. Rees. 2022.
“Estimating the Effects of Milk Inspections on Infant and Child Mortality, 1880−1910.”
AEA Papers and Proceedings 112 (May):188–92.
https://doi.org/10.1257/PANDP.20221066.
Anderson, D. Mark, Kerwin Kofi Charles, Claudio Las Heras Olivares, and Daniel I. Rees. 2019.
“Was the First Public Health Campaign Successful?” American Economic Journal: Applied
Economics 11 (2): 143–75. https://doi.org/10.1257/APP.20170411.
Anderson, D. Mark, Kerwin Kofi Charles, and Daniel I. Rees. 2022. “Reexamining the
Contribution of Public Health Efforts to the Decline in Urban Mortality.” American
Economic Journal: Applied Economics 14 (2): 126–57.
https://doi.org/10.1257/APP.20190034.
Apergis, Nicholas, Tasawar Hayat, and Tareq Saeed. 2019. “Fracking and Infant Mortality:
Fresh Evidence from Oklahoma.” Environmental Science and Pollution Research 26 (31):
32360–67. https://doi.org/10.1007/S11356-019-06478-Z/TABLES/5.
Armstrong, Gregory L., Laura A. Conn, and Robert W. Pinner. 1999. “Trends in Infectious
Disease Mortality in the United States During the 20th Century.” JAMA 281 (1): 61–66.
https://doi.org/10.1001/JAMA.281.1.61.
Bailey, Martha, Karen Clay, Price Fishback, Michael Haines, Shawn Kantor, Edson Severnini,
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
28
and Anna Wentz. 2016. “U.S. County-Level Natality and Mortality Data, 1915-2007.”
Inter-University Consortium for Political and Social Research.
https://doi.org/https://doi.org/10.3886/E100229V4.
Barker, D. J.P. 1994. Mothers, Babies, and Disease in Later Life. BMJ publishing group London.
———. 1995. “Fetal Origins of Coronary Heart Disease.” BMJ 311 (6998): 171–74.
https://doi.org/10.1136/BMJ.311.6998.171.
———. 1997. “Maternal Nutrition, Fetal Nutrition, and Disease in Later Life.” Nutrition 13 (9):
807–13. https://doi.org/10.1016/S0899-9007(97)00193-7.
———. 2004. “The Developmental Origins of Adult Disease.” Journal of the American College
of Nutrition 23 (December):588S-595S. https://doi.org/10.1080/07315724.2004.10719428.
Beach, Brian, Joseph Ferrie, Martin Saavedra, and Werner Troesken. 2016. “Typhoid Fever,
Water Quality, and Human Capital Formation.” The Journal of Economic History 76 (1):
41–75. https://doi.org/10.1017/S0022050716000413.
Behrman, Jere R, and Mark R Rosenzweig. 2004. “Returns to Birthweight.” Review of
Economics and Statistics. https://doi.org/10.1162/003465304323031139.
Beland, Louis Philippe, and Sara Oloomi. 2019. “Environmental Disaster, Pollution and Infant
Health: Evidence from the Deepwater Horizon Oil Spill.” Journal of Environmental
Economics and Management 98 (November):102265.
https://doi.org/10.1016/J.JEEM.2019.102265.
Benítez-Silva, Hugo, and Huan Ni. 2008. “Health Status and Health Dynamics in an Empirical
Model of Expected Longevity.” Journal of Health Economics 27 (3): 564–84.
https://doi.org/10.1016/J.JHEALECO.2007.09.008.
Berg, Gerard J. Van Den, Gabriele Doblhammer-Reiter, Kaare Christensen, Gerard J den Berg,
Gabriele Doblhammer-Reiter, Kaare Christensen, Gerard J van den Berg, et al. 2011.
“Being Born under Adverse Economic Conditions Leads to a Higher Cardiovascular
Mortality Rate Later in Life: Evidence Based on Individuals Born at Different Stages of the
Business Cycle.” Demography 48 (2): 507–30. https://doi.org/10.1007/s13524-011-0021-8.
Berg, Gerard J. Van Den, Gabriele Doblhammer, and Kaare Christensen. 2009. “Exogenous
Determinants of Early-Life Conditions, and Mortality Later in Life.” Social Science &
Medicine 68 (9): 1591–98. https://doi.org/10.1016/J.SOCSCIMED.2009.02.007.
Berg, Gerard J. Van Den, Sumedha Gupta, Gerard J van den Berg, and Sumedha Gupta. 2015.
“The Role of Marriage in the Causal Pathway from Economic Conditions Early in Life to
Mortality.” Journal of Health Economics 40:141–58.
https://doi.org/10.1016/j.jhealeco.2014.02.004.
Berg, Gerard J. Van Den, Maarten Lindeboom, France Portrait, Gerard J Van Den Berg, Maarten
Lindeboom, France Portrait, Gerard J den Berg, Maarten Lindeboom, and France Portrait.
2006. “Economic Conditions Early in Life and Individual Mortality.” American Economic
Review 96 (1): 290–302. https://doi.org/10.1257/000282806776157740.
Black, Sandra E, Paul J Devereux, and Kjell G Salvanes. 2007. “From the Cradle to the Labor
Market? The Effect of Birth Weight on Adult Outcomes.” The Quarterly Journal of
Economics 122 (1): 409–39. https://doi.org/10.1162/qjec.122.1.409.
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
29
Blackwell, Debra L., Mark D. Hayward, and Eileen M. Crimmins. 2001. “Does Childhood
Health Affect Chronic Morbidity in Later Life?” Social Science & Medicine 52 (8): 1269–
84. https://doi.org/10.1016/S0277-9536(00)00230-6.
Bleakley, Hoyt. 2007. “Disease and Development: Evidence from Hookworm Eradication in the
American South.” The Quarterly Journal of Economics 122 (1): 73–117.
https://doi.org/10.1162/QJEC.121.1.73.
Borusyak, Kirill, Xavier Jaravel, and Jann Spiess. 2021. “Revisiting Event Study Designs:
Robust and Efficient Estimation,” August. https://arxiv.org/abs/2108.12419v1.
Bozzoli, Carlos, Angus Deaton, and Climent Quintana-Domeque. 2009. “Adult Height and
Childhood Disease.” Demography 46 (4): 647–69. https://doi.org/10.1353/DEM.0.0079.
Brainerd, Elizabeth, and Nidhiya Menon. 2014. “Seasonal Effects of Water Quality: The Hidden
Costs of the Green Revolution to Infant and Child Health in India.” Journal of Development
Economics 107 (March):49–64. https://doi.org/10.1016/J.JDEVECO.2013.11.004.
Breen, Casey F., and Maria Osborne. 2022. “An Assessment of CenSoc Match Quality,” June.
https://doi.org/10.31235/OSF.IO/BJ5MD.
Breen, Casey F., Maria Osborne, and Joshua R. Goldstein. 2023. “CenSoc: Public Linked
Administrative Mortality Records for Individual-Level Research.” Scientific Data 2023
10:1 10 (1): 1–12. https://doi.org/10.1038/s41597-023-02713-y.
Callaway, Brantly, and Pedro H.C. Sant’Anna. 2021. “Difference-in-Differences with Multiple
Time Periods.” Journal of Econometrics 225 (2): 200–230.
https://doi.org/10.1016/J.JECONOM.2020.12.001.
Case, Anne, Angela Fertig, and Christina Paxson. 2005. “The Lasting Impact of Childhood
Health and Circumstance.” Journal of Health Economics 24 (2): 365–89.
https://doi.org/10.1016/J.JHEALECO.2004.09.008.
Case, Anne, and Christina Paxson. 2009. “Early Life Health and Cognitive Function in Old
Age.” American Economic Review 99 (2): 104–9. https://doi.org/10.1257/AER.99.2.104.
CDC. 2015. “Vital Statistics of the US 1890-1938.” 2015.
https://www.cdc.gov/nchs/products/vsus/vsus_1890_1938.htm.
Chetty, Raj, Michael Stepner, Sarah Abraham, Shelby Lin, Benjamin Scuderi, Nicholas Turner,
Augustin Bergeron, and David Cutler. 2016. “The Association Between Income and Life
Expectancy in the United States, 2001-2014.” JAMA 315 (16): 1750–66.
https://doi.org/10.1001/JAMA.2016.4226.
Chou, Shin Yi, Michael Grossman, and Henry Saffer. 2006. “Reply to Jonathan Gruber and
Michael Frakes.” Journal of Health Economics 25 (2): 389–93.
https://doi.org/10.1016/J.JHEALECO.2005.12.004.
Clay, Karen, Werner Troesken, and Michael Haines. 2014. “Lead and Mortality.” The Review of
Economics and Statistics 96 (3): 458–70. https://doi.org/10.1162/REST_A_00396.
Condran, Gretchen A., and Eileen Crimmins-Gardner. 1978. “Public Health Measures and
Mortality in U.S. Cities in the Late Nineteenth Century.” Human Ecology 6 (1): 27–54.
https://doi.org/10.1007/BF00888565/METRICS.
Cook, C. Justin, Jason M. Fletcher, and Angela Forgues. 2019. “Multigenerational Effects of
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
30
Early-Life Health Shocks.” Demography 56 (5): 1855–74. https://doi.org/10.1007/S13524-
019-00804-3.
Cook, C Justin, and Jason M Fletcher. 2015. “Understanding Heterogeneity in the Effects of
Birth Weight on Adult Cognition and Wages.” Journal of Health Economics 41:107–16.
https://doi.org/10.1016/j.jhealeco.2015.01.005.
Cormack, Louise, Volha Lazuka, and Luciana Quaranta. 2024. “Early-Life Disease Exposure
and Its Heterogeneous Effects on Mortality Throughout Life: Sweden, 1905–2016.”
Demography 61 (4): 1187–1210. https://doi.org/10.1215/00703370-11466677.
Costa, Dora L. 2015. “Health and the Economy in the United States from 1750 to the Present.”
Journal of Economic Literature. American Economic Association.
https://doi.org/10.1257/jel.53.3.503.
Crimmins, Eileen M., and Caleb E. Finch. 2006. “Infection, Inflammation, Height, and
Longevity.” Proceedings of the National Academy of Sciences of the United States of
America 103 (2): 498–503.
https://doi.org/10.1073/PNAS.0501470103/SUPPL_FILE/01470FIG4.PDF.
Cristia, Julian P. 2009. “Rising Mortality and Life Expectancy Differentials by Lifetime
Earnings in the United States.” Journal of Health Economics 28 (5): 984–95.
https://doi.org/10.1016/J.JHEALECO.2009.06.003.
Currie, Janet, Joshua Graff Zivin, Katherine Meckel, Matthew Neidell, and Wolfram Schlenker.
2013. “Something in the Water: Contaminated Drinking Water and Infant Health.”
Canadian Journal of Economics/Revue Canadienne d’économique 46 (3): 791–810.
https://doi.org/10.1111/CAJE.12039.
Currie, Janet, Michael Greenstone, and Katherine Meckel. 2017. “Hydraulic Fracturing and
Infant Health: New Evidence from Pennsylvania.” Science Advances 3 (12).
https://doi.org/10.1126/SCIADV.1603021/SUPPL_FILE/1603021_SM.PDF.
Currie, Janet, and Hannes Schwandt. 2013. “Within-Mother Analysis of Seasonal Patterns in
Health at Birth.” Proceedings of the National Academy of Sciences of the United States of
America 110 (30): 12265–70.
https://doi.org/10.1073/PNAS.1307582110/SUPPL_FILE/PNAS.201307582SI.PDF.
Cutler, David, Angus Deaton, and Adriana Lleras-Muney. 2006. “The Determinants of
Mortality.” Journal of Economic Perspectives 20 (3): 97–120.
https://doi.org/10.1257/JEP.20.3.97.
Cutler, David M., and Adriana Lleras-Muney. 2006. “Education and Health: Evaluating Theories
and Evidence.” National Bureau of Economic Research, July, 37.
https://doi.org/10.3386/W12352.
Cutler, David M, Grant Miller, and Douglas M Norton. 2007. “Evidence on Early-Life Income
and Late-Life Health from America’s Dust Bowl Era.” Proceedings of the National
Academy of Sciences 104 (33): 13244–49.
Cutler, David, and Grant Miller. 2005. “The Role of Public Health Improvements in Health
Advances: The Twentieth-Century United States.” Demography 2005 42:1 42 (1): 1–22.
https://doi.org/10.1353/DEM.2005.0002.
Deaton, Angus. 2007. “Height, Health, and Development.” Proceedings of the National
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
31
Academy of Sciences 104 (33): 13232–37. https://doi.org/10.1073/PNAS.0611500104.
Deaton, Angus, and Raksha Arora. 2009. “Life at the Top: The Benefits of Height.” Economics
and Human Biology 7 (2): 133–36. https://doi.org/10.1016/j.ehb.2009.06.001.
Diener, Ed, and Micaela Y. Chan. 2011. “Happy People Live Longer: Subjective Well-Being
Contributes to Health and Longevity.” Applied Psychology: Health and Well-Being 3 (1):
1–43. https://doi.org/10.1111/J.1758-0854.2010.01045.X.
Doblhammer, G., and J. W. Vaupel. 2001. “Lifespan Depends on Month of Birth.” Proceedings
of the National Academy of Sciences of the United States of America 98 (5): 2934–39.
https://doi.org/10.1073/PNAS.041431898/SUPPL_FILE/4318FIG5.PDF.
Falagas, Matthew E., Drosos E. Karageorgopoulos, Lambros I. Moraitis, Evridiki K.
Vouloumanou, Nikos Roussos, George Peppas, and Petros I. Rafailidis. 2009. “Seasonality
of Mortality: The September Phenomenon in Mediterranean Countries.” Canadian Medical
Association Journal 181 (8): 484–86. https://doi.org/10.1503/CMAJ.090694.
Ferrie, Joseph P, and Werner Troesken. 2008. “Water and Chicago’s Mortality Transition, 1850-
-1925.” Explorations in Economic History 45 (1): 1–16.
Finch, Caleb E., and Eileen M. Crimmins. 2004. “Inflammatory Exposure and Historical
Changes in Human Life-Spans.” Science 305 (5691): 1736–39.
https://doi.org/10.1126/SCIENCE.1092556/ASSET/02F255E8-C8D1-46C1-B84F-
0E0CD47778A7/ASSETS/GRAPHIC/ZSE0360428410001.JPEG.
Fletcher, Jason M. 2018a. “Environmental Bottlenecks in Children’s Genetic Potential for Adult
Socio-Economic Attainments: Evidence from a Health Shock.” Population Studies 73 (1):
139–48. https://doi.org/10.1080/00324728.2018.1498533.
———. 2018b. “Examining the Long-Term Mortality Effects of Early Health Shocks.” Applied
Economics Letters 26 (11): 902–8. https://doi.org/10.1080/13504851.2018.1520960.
Fletcher, Jason M. 2011. “The Medium Term Schooling and Health Effects of Low Birth
Weight: Evidence from Siblings.” Economics of Education Review 30 (3): 517–27.
https://doi.org/10.1016/j.econedurev.2010.12.012.
———. 2015. “New Evidence of the Effects of Education on Health in the US: Compulsory
Schooling Laws Revisited.” Social Science & Medicine 127 (February):101–7.
https://doi.org/10.1016/J.SOCSCIMED.2014.09.052.
Fletcher, Jason, and Hamid Noghanibehambari. 2024. “The Siren Song of Cicadas: Early-Life
Pesticide Exposure and Later-Life Male Mortality.” Journal of Environmental Economics
and Management 123 (January):102903. https://doi.org/10.1016/J.JEEM.2023.102903.
Fletcher, Jason, Michael Topping, Fengyi Zheng, and Qiongshi Lu. 2021. “The Effects of
Education on Cognition in Older Age: Evidence from Genotyped Siblings.” Social Science
& Medicine 280 (July):114044. https://doi.org/10.1016/J.SOCSCIMED.2021.114044.
Friedrich, M. 1912. “The Mills--Reincke Phenomenon.” Ohio State Medical Journal 20:514–17.
Gardner, Jonathan, and Andrew Oswald. 2004. “How Is Mortality Affected by Money, Marriage,
and Stress?” Journal of Health Economics 23 (6): 1181–1207.
https://doi.org/10.1016/J.JHEALECO.2004.03.002.
Goldstein, Joshua R, Monica Alexander, Casey Breen, Andrea Miranda González, Felipe
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
32
Menares, Maria Osborne, Mallika Snyder, and Ugur Yildirim. 2021. “Censoc Project.”
CenSoc Mortality File: Version 2.0. Berkeley: University of California.
https://censoc.berkeley.edu/data/.
Goodman-Bacon, Andrew. 2021. “Difference-in-Differences with Variation in Treatment
Timing.” Journal of Econometrics, June. https://doi.org/10.1016/J.JECONOM.2021.03.014.
Greenstone, Michael, and Rema Hanna. 2014. “Environmental Regulations, Air and Water
Pollution, and Infant Mortality in India.” American Economic Review. American Economic
Association. https://doi.org/10.1257/aer.104.10.3038.
Grossman, Daniel S., and David J.G. Slusky. 2019. “The Impact of the Flint Water Crisis on
Fertility.” Demography 56 (6): 2005–31. https://doi.org/10.1007/S13524-019-00831-0.
Gruber, Jonathan, and Michael Frakes. 2006. “Does Falling Smoking Lead to Rising Obesity?”
Journal of Health Economics 25 (2): 183–97.
https://doi.org/10.1016/J.JHEALECO.2005.07.005.
Hafeman, Danella, Pam Factor-Litvak, Zhonggi Cheng, Alexander van Geen, and Habibul
Ahsan. 2007. “Association between Manganese Exposure through Drinking Water and
Infant Mortality in Bangladesh.” Environmental Health Perspectives 115 (7): 1107–12.
https://doi.org/10.1289/EHP.10051.
Halpern-Manners, Andrew, Jonas Helgertz, John Robert Warren, and Evan Roberts. 2020. “The
Effects of Education on Mortality: Evidence From Linked U.S. Census and Administrative
Mortality Data.” Demography 57 (4): 1513–41. https://doi.org/10.1007/S13524-020-00892-
6.
Hayward, Mark D, and Bridget K Gorman. 2004. “The Long Arm of Childhood: The Influence
of Early-Life Social Conditions on Men’s Mortality.” Demography 2004 41:1 41 (1): 87–
107. https://doi.org/10.1353/DEM.2004.0005.
He, Guojun, and Jeffrey M Perloff. 2016. “Surface Water Quality and Infant Mortality in China.”
Economic Development and Cultural Change 65 (1): 119–39.
https://doi.org/10.1086/687603.
Hill, Elaine L., and Lala Ma. 2022. “Drinking Water, Fracking, and Infant Health.” Journal of
Health Economics 82 (March):102595. https://doi.org/10.1016/J.JHEALECO.2022.102595.
Hill, Elaine L. 2018. “Shale Gas Development and Infant Health: Evidence from Pennsylvania.”
Journal of Health Economics 61:134–50. https://doi.org/10.1016/j.jhealeco.2018.07.004.
Huebener, Mathias. 2019. “Life Expectancy and Parental Education.” Social Science & Medicine
232 (July):351–65. https://doi.org/10.1016/J.SOCSCIMED.2019.04.034.
———. 2020. “Parental Education and Children’s Health throughout Life.” The Economics of
Education: A Comprehensive Overview, January, 91–102. https://doi.org/10.1016/B978-0-
12-815391-8.00007-0.
Jones, Benjamin A. 2019. “Infant Health Impacts of Freshwater Algal Blooms: Evidence from an
Invasive Species Natural Experiment.” Journal of Environmental Economics and
Management 96 (July):36–59. https://doi.org/10.1016/J.JEEM.2019.05.002.
Jousilahti, Pekka, Jaakko Tuomilehto, Erkki Vartiainen, Johan Eriksson, and Pekka Puska. 2000.
“Relation of Adult Height to Cause-Specific and Total Mortality: A Prospective Follow-up
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
33
Study of 31, 199 Middle-Aged Men and Women in Finland.” American Journal of
Epidemiology 151 (11): 1112–20.
https://doi.org/10.1093/OXFORDJOURNALS.AJE.A010155.
Kinge, Jonas Minet, Jørgen Heibø Modalsli, Simon Øverland, Håkon Kristian Gjessing, Mette
Christophersen Tollånes, Ann Kristin Knudsen, Vegard Skirbekk, Bjørn Heine Strand, Siri
Eldevik Håberg, and Stein Emil Vollset. 2019. “Association of Household Income With
Life Expectancy and Cause-Specific Mortality in Norway, 2005-2015.” JAMA 321 (19):
1916–25. https://doi.org/10.1001/JAMA.2019.4329.
Kniesner, Thomas J., and W. Kip Viscusi. 2019. “The Value of a Statistical Life.” Oxford
Research Encyclopedia of Economics and Finance, July.
https://doi.org/10.1093/ACREFORE/9780190625979.013.138.
Kose, Esra, Elira Kuka, and Na’ama Shenhav. 2021. “Women’s Suffrage and Children’s
Education.” American Economic Journal: Economic Policy 13 (3): 374–405.
https://doi.org/10.1257/POL.20180677.
Kunitz, Stephan J. 1984. “Mortality Change in America, 1620-1920.” Human Biology, 559–82.
Lee, Jin Young, and Gary Solon. 2011. “The Fragility of Estimated Effects of Unilateral Divorce
Laws on Divorce Rates.” B.E. Journal of Economic Analysis and Policy 11 (1).
https://doi.org/10.2202/1935-1682.2994/MACHINEREADABLECITATION/RIS.
Lindeboom, Maarten, France Portrait, and Gerard J. Van Den Berg. 2010. “Long-Run Effects on
Longevity of a Nutritional Shock Early in Life: The Dutch Potato Famine of 1846–1847.”
Journal of Health Economics 29 (5): 617–29.
https://doi.org/10.1016/J.JHEALECO.2010.06.001.
Lleras-Muney, Adriana. 2005. “The Relationship Between Education and Adult Mortality in the
United States.” The Review of Economic Studies 72 (1): 189–221.
https://doi.org/10.1111/0034-6527.00329.
———. 2022. “Education and Income Gradients in Longevity: The Role of Policy.” Canadian
Journal of Economics/Revue Canadienne d’économique 55 (1): 5–37.
https://doi.org/10.1111/CAJE.12582.
Lleras-Muney, Adriana, and Flavien Moreau. 2022. “A Unified Model of Cohort Mortality.”
Demography 59 (6): 2109–34. https://doi.org/10.1215/00703370-10286336.
Lleras-Muney, Adriana, Joseph Price, and Dahai Yue. 2022. “The Association between
Educational Attainment and Longevity Using Individual-Level Data from the 1940
Census.” Journal of Health Economics 84 (July):102649.
https://doi.org/10.1016/J.JHEALECO.2022.102649.
Lundborg, Petter, Anton Nilsson, and Dan-Olof Rooth. 2014. “Parental Education and Offspring
Outcomes: Evidence from the Swedish Compulsory School Reform.” American Economic
Journal: Applied Economics 6 (1): 253–78. https://doi.org/10.1257/APP.6.1.253.
Maruyama, Shiko, and Eskil Heinesen. 2020. “Another Look at Returns to Birthweight.” Journal
of Health Economics 70 (March):102269. https://doi.org/10.1016/j.jhealeco.2019.102269.
McGee, Harold G. 1920. “Mills-Reincke Phenomenon and Typhoid Control by Vaccine.”
American Journal of Public Health 10 (7): 585–87.
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
34
Meer, Jonathan, and Jeremy West. 2016. “Effects of the Minimum Wage on Employment
Dynamics.” Journal of Human Resources 51 (2): 500–522.
https://doi.org/10.3368/JHR.51.2.0414-6298R1.
Mettetal, Elizabeth. 2019. “Irrigation Dams, Water and Infant Mortality: Evidence from South
Africa.” Journal of Development Economics 138 (May):17–40.
https://doi.org/10.1016/J.JDEVECO.2018.11.002.
Montez, Jennifer, and Mark D Hayward. 2014. “Cumulative Childhood Adversity, Educational
Attainment, and Active Life Expectancy Among U.S. Adults.” Demography 51 (2): 413–35.
https://doi.org/10.1007/S13524-013-0261-X.
Moore, Sophie E., Andrew C. Collinson, Pa Tamba N’Gom, Richard Aspinall, and Andrew M.
Prentice. 2006. “Early Immunological Development and Mortality from Infectious Disease
in Later Life.” Proceedings of the Nutrition Society 65 (3): 311–18.
https://doi.org/10.1079/PNS2006503.
Mueller, J. Tom, and Stephen Gasteyer. 2021. “The Widespread and Unjust Drinking Water and
Clean Water Crisis in the United States.” Nature Communications 2021 12:1 12 (1): 1–8.
https://doi.org/10.1038/s41467-021-23898-z.
Myrskylä, Mikko, Neil K. Mehta, and Virginia W. Chang. 2013. “Early Life Exposure to the
1918 Influenza Pandemic and Old-Age Mortality by Cause of Death.” American Journal of
Public Health 103 (7). https://doi.org/10.2105/AJPH.2012.301060.
Nadimpalli, Maya L., Val F. Lanza, Maria Camila Montealegre, Sonia Sultana, Erica R.
Fuhrmeister, Colin J. Worby, Lisa Teichmann, et al. 2022. “Drinking Water Chlorination
Has Minor Effects on the Intestinal Flora and Resistomes of Bangladeshi Children.” Nature
Microbiology 2022 7:5 7 (5): 620–29. https://doi.org/10.1038/s41564-022-01101-3.
Neumark, David, J. M.Ian Salas, and William Wascher. 2014. “Revisiting the Minimum Wage—
Employment Debate: Throwing Out the Baby with the Bathwater?:” ILR Review 67
(SUPPL): 608–48. https://doi.org/10.1177/00197939140670S307.
Noghanibehambari, Hamid, and Michal Engelman. 2022. “Social Insurance Programs and Later-
Life Mortality: Evidence from New Deal Relief Spending.” Journal of Health Economics
86 (December). https://doi.org/10.1016/J.JHEALECO.2022.102690.
Noghanibehambari, Hamid, and Jason Fletcher. 2023a. “Childhood Exposure to Birth
Registration Laws and Old-Age Mortality.” Health Economics 32 (3): 735–43.
https://doi.org/10.1002/HEC.4643.
———. 2023b. “In Utero and Childhood Exposure to Alcohol and Old Age Mortality: Evidence
from the Temperance Movement in the US.” Economics & Human Biology 50
(August):101276. https://doi.org/10.1016/J.EHB.2023.101276.
———. 2023c. “Long-Term Health Benefits of Occupational Licensing: Evidence from
Midwifery Laws.” Journal of Health Economics 92 (December):102807.
https://doi.org/10.1016/J.JHEALECO.2023.102807.
Noghanibehambari, Hamid, and Jason M. Fletcher. 2023d. “Dust to Feed, Dust to Grey: The
Effect of In-Utero Exposure to the Dust Bowl on Old-Age Longevity.” Demography,
October. https://doi.org/10.3386/W30531.
Noghanibehambari, Hamid, Jason Fletcher, Lauren Schmitz, Valentina Duque, and Vikas Gawai.
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
35
2024. “Early-Life Economic Conditions and Old-Age Male Mortality: Evidence from
Historical County-Level Bank Deposit Data.” Journal of Population Economics 37 (1): 1–
33. https://doi.org/10.1007/S00148-024-01007-W/TABLES/7.
Noghanibehambari, Hamid, and Farzaneh Noghani. 2023. “Long-Run Intergenerational Health
Benefits of Women Empowerment: Evidence from Suffrage Movements in the US.” Health
Economics, July. https://doi.org/10.1002/HEC.4744.
Noghanibehambari, Hamid, Mahmoud Salari, and Nahid Tavassoli. 2022. “Maternal Human
Capital and Infants’ Health Outcomes: Evidence from Minimum Dropout Age Policies in
the US.” SSM - Population Health 19 (September):101163.
https://doi.org/10.1016/J.SSMPH.2022.101163.
Palloni, Alberto, and Hantamala Rafalimanana. 1999. “The Effects of Infant Mortality on
Fertility Revisited: New Evidence from Latin America.” Demography 1999 36:1 36 (1):
41–58. https://doi.org/10.2307/2648133.
Potter, Guy G., Michael J. Helms, and Brenda L. Plassman. 2008. “Associations of Job Demands
and Intelligence with Cognitive Performance among Men in Late Life.” Neurology 70 (19
PART 2): 1803–8.
https://doi.org/10.1212/01.WNL.0000295506.58497.7E/ASSET/621CF9B5-EF81-4C8C-
8B52-D156DD04EBBD/ASSETS/GRAPHIC/12FSM1.GIF.
Preston, Samuel H. 2005. “Deadweight? — The Influence of Obesity on Longevity.” The New
England Journal of Medicine 352 (11): 1135–37. https://doi.org/10.1056/NEJME058009.
Royer, Heather. 2009. “Separated at Girth: US Twin Estimates of the Effects of Birth Weight.”
American Economic Journal: Applied Economics 1 (1): 49–85.
https://doi.org/10.1257/app.1.1.49.
Ruggles, Steven, Sarah Flood, Ronald Goeken, Josiah Grover, and Erin Meyer. 2020. “IPUMS
USA: Version 10.0 [Dataset].” Minneapolis, MN: IPUMS.
https://doi.org/10.18128/D010.V10.0.
Sandberg, John. 2016. “Infant Mortality, Social Networks, and Subsequent Fertility:” American
Sociological Review 71 (2): 288–309. https://doi.org/10.1177/000312240607100206.
Scholte, Robert S., Gerard J. Van Den Berg, and Maarten Lindeboom. 2015. “Long-Run Effects
of Gestation during the Dutch Hunger Winter Famine on Labor Market and Hospitalization
Outcomes.” Journal of Health Economics 39 (January):17–30.
https://doi.org/10.1016/J.JHEALECO.2014.10.002.
Seretakis, Dimitrios, Pagona Lagiou, Loren Lipworth, Lisa B. Signorello, Kenneth J. Rothman,
and Dimitrios Trichopoulos. 1997. “Changing Seasonality of Mortality From Coronary
Heart Disease.” JAMA 278 (12): 1012–14.
https://doi.org/10.1001/JAMA.1997.03550120072036.
Shenkin, Susan D., Ian J. Deary, and John M. Starr. 2009. “Birth Parameters and Cognitive
Ability in Older Age: A Follow-Up Study of People Born 1921–1926.” Gerontology 55 (1):
92–98. https://doi.org/10.1159/000163444.
Smith, Allan H., Guillermo Marshall, Jane Liaw, Yan Yuan, Catterina Ferreccio, and Craig
Steinmaus. 2012. “Mortality in Young Adults Following in Utero and Childhood Exposure
to Arsenic in Drinking Water.” Environmental Health Perspectives 120 (11): 1527–31.
This is the author's accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of American
Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.
36
https://doi.org/10.1289/EHP.1104867.
Smith, Allan H., Guillermo Marshall, Yan Yuan, Catterina Ferreccio, Jane Liaw, Ondine von
Ehrenstein, Craig Steinmaus, Michael N. Bates, and Steve Selvin. 2006. “Increased
Mortality from Lung Cancer and Bronchiectasis in Young Adults after Exposure to Arsenic
in Utero and in Early Childhood.” Environmental Health Perspectives 114 (8): 1293–96.
https://doi.org/10.1289/EHP.8832.
Smith, David W., and Benjamin S. Bradshaw. 2006. “Variation in Life Expectancy during the
Twentieth Century in The United States.” Demography 2006 43:4 43 (4): 647–57.
https://doi.org/10.1353/DEM.2006.0039.
Smith, James P. 2009. “The Impact of Childhood Health on Adult Labor Market Outcomes.” The
Review of Economics and Statistics 91 (3): 478–89. https://doi.org/10.1162/REST.91.3.478.
Spijker, Jeroen J.A., Antonio D. Cámara, and Amand Blanes. 2012. “The Health Transition and
Biological Living Standards: Adult Height and Mortality in 20th-Century Spain.”
Economics & Human Biology 10 (3): 276–88. https://doi.org/10.1016/J.EHB.2011.08.001.
SSA. 2020. “Social Security Program Data.” 2020.
https://www.ssa.gov/oact/HistEst/CohLifeTables/2020/CohLifeTables2020.html.
Sun, Liyang, and Sarah Abraham. 2021. “Estimating Dynamic Treatment Effects in Event
Studies with Heterogeneous Treatment Effects.” Journal of Econometrics 225 (2): 175–99.
https://doi.org/10.1016/J.JECONOM.2020.09.006.
Troesken, Werner. 2004. Race, Water, and Disease. Cambridge: MIT Press.
UNICEF. 2021. “Progress on Household Drinking Water, Sanitation and Hygiene, 2000-2020:
Five Years into the SDGs - UNICEF DATA.” https://data.unicef.org/resources/progress-on-
household-drinking-water-sanitation-and-hygiene-2000-2020/.
Venkataramani, Atheendar S. 2012. “Early Life Exposure to Malaria and Cognition in
Adulthood: Evidence from Mexico.” Journal of Health Economics 31 (5): 767–80.
https://doi.org/10.1016/J.JHEALECO.2012.06.003.
Viscusi, W. Kip. 2018. “Best Estimate Selection Bias in the Value of a Statistical Life.” Journal
of Benefit-Cost Analysis 9 (2): 205–46. https://doi.org/10.1017/BCA.2017.21.
WHO. 2019. Progress on Household Drinking Water, Sanitation and Hygiene 2000-2017:
Special Focus on Inequalities. World Health Organization.
Wilson, Sven E. 2019. “Does Adult Height Predict Later Mortality?: Comparative Evidence
from the Early Indicators Samples in the United States.” Economics & Human Biology 34
(August):274–85. https://doi.org/10.1016/J.EHB.2019.05.004.
Zaveri, Esha, Jason Russ, Sebastien Desbureaux, Richard Damania, Aude-Sophie Rodella, and
Giovanna Ribeiro. 2019. “The Nitrogen Legacy : The Long-Term Effects of Water
Pollution on Human Capital.” The Nitrogen Legacy, December.
https://doi.org/10.1596/33073.
Zhang, Jing, and Lixin Colin Xu. 2016. “The Long-Run Effects of Treated Water on Education:
The Rural Drinking Water Program in China.” Journal of Development Economics 122
(September):1–15. https://doi.org/10.1016/J.JDEVECO.2016.04.004.
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Tables
Table 1 - Summary Statistics
Variable
Mean
Std. Dev.
Min
Max
Death Age (Months)
867.238
123.454
420
1249
Birth Year
1919.480
8.438
1900
1940
Death Year
1991.749
8.619
1975
2005
White
.975
.154
0
1
Black
.024
.154
0
1
Hispanic
.008
.089
0
1
Mother Literate
.909
.287
0
1
Mother Literacy Missing
.017
.129
0
1
Mother in Labor Force
.058
.235
0
1
Father Literate
.900
.299
0
1
Father Literacy Missing
.037
.189
0
1
Father in Labor Force
.945
.226
0
1
Father Occupational Income Score
28.407
9.174
3
80
Father Occupational Income Score
Missing
.084
.278
0
1
Water Filtration
.156
.362
0
1
Chlorination of Water
.753
.422
0
1
Bacteriological Standard for Milk
.767
.415
0
1
Sewage Treatment or Diversion
.333
.468
0
1
Observations
338,758
Census 1960-1980 Data:
Year of Schooling
10.693
3.684
0
18
Education less than High School
.118
.323
0
1
Education < 12
.501
.500
0
1
Socioeconomic Index
38.282
23.373
3
96
Total Family Income
72303.89
45351.124
43.718
874361.5
Ln Total Family Income
11.001
.668
3.777
13.681
Year of birth
1920.487
10.869
1900
1940
White
.833
.372
0
1
Black
.163
.369
0
1
Hispanic
.009
.095
0
1
Observations
362,167
WWII Enlistment Data:
Army General Classification Test
(AGCT) score
140.517
12.919
2
160
Log AGCT
4.940
.112
.693
5.075
Height
2.722
.414
.034
4.5
Log Height
.988
.171
-3.367
1.504
Nonwhite
.019
.139
0
1
Observations
33,139
Birth/Death Data:
Infant Mortality Rate per 100,000
66.344
21.642
28.059
148.979
Log Infant Mortality Rate per
4.141
.328
3.334
5.003
Birth per 1,000 Women
37.875
8.238
22.906
69.283
Log Birth Rate
3.639
.204
3.174
4.252
Observations
559
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Table 2 - Main Results: Childhood Exposure to Water Filtration and Later Life Longevity
Outcomes: Age at Death (Months)
(1)
(2)
(3)
Exposure to Water
Filtration
3.68*
3.23**
3.24**
(1.76)
(1.51)
(1.11)
Observations
338758
338758
338742
R-squared
.35
.35
.35
Mean DV
867.23
867.23
867.24
P-Value
0.07
0.05
0.03
City FE
Birth Year FE
Individual Controls
Family Controls
City Controls
Region-by-Cohort FE
Notes. Standard errors, clustered on city, are in parentheses. P-values are extracted from the wild bootstrap
procedure with city-level clustering. Individual controls include dummies for race and ethnicity. Family controls
include maternal literacy dummy, paternal literacy dummy, maternal labor force status dummy, paternal labor force
status dummy, paternal socioeconomic score dummies, and a series of missing indicators for missing values of each
variable. City controls include average share of homeowners, average occupational income score, share of white-
collar occupation, share of farmers, share of other occupation, literacy rate, and share of married.
*** p<0.01, ** p<0.05, * p<0.1
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Table 3 - Exploring Endogenous Merging
Outcome: Successful Merging between the Final Sample and the Original
Population in 1940
Full Sample
Whites
Nonwhites
(1)
(2)
(3)
Exposure to Water
Filtration
-.0002
.0001
.0003
(.0077)
(.0078)
(.0082)
Observations
7218487
6844592
373895
R-squared
.0057
.0058
.004
Mean DV
0.033
0.034
0.015
P-Value
0.978
0.987
0.966
Notes. Standard errors, clustered on city, are in parentheses. P-values are extracted from the wild bootstrap
procedure with city-level clustering. Regressions include city and region-by-year fixed effects. Regressions also
include city covariates. City controls include average share of homeowners, average occupational income score,
share of white-collar occupation, share of farmers, share of other occupation, literacy rate, and share of married.
*** p<0.01, ** p<0.05, * p<0.1
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Table 4 - Robustness Checks
Outcome: Age at Death (Months)
Column 3 of Table 2
Adding Birth-State by
1940-State FE
Adding City-by-
Individual Covariates
Interaction
Adding City-by-
Parental Covariates
Interaction
Adding Birth-Month
and Death-Month FE
Adding
more City
Controls
(1)
(2)
(3)
(4)
(5)
(6)
Exposure to
Water
Filtration
3.24**
3.23**
3.20**
3.62**
3.25***
2.90*
(1.11)
(1.14)
(1.09)
(1.25)
(1.10)
(1.31)
Observations
338758
338758
338758
310097
338758
306759
R-squared
.35
.35
.35625
.35655
.35687
.22901
Mean DV
867.23
867.23
867.23
867.17
867.23
883.28
P-Value
0.02
0.03
0.03
0.03
0.01
0.09
Using
Heteroscedasticity
Robust SE
Outcome: Log Age at
Death
Outcome: Age at
Death>75
Weighted by City
Population
Dropping Cohorts of
1918-1919
Dropping
Cohorts of
1930-1940
(7)
(8)
(9)
(10)
(11)
(12)
Exposure to
Water
Filtration
3.24**
.003***
.014**
3.85***
3.46***
3.10**
(1.55)
(.001)
(.006)
(.75)
(1.06)
(1.19)
Observations
338758
338758
338758
338758
307954
306185
R-squared
.35
.36
.18
.38
.37
.22
Mean DV
867.23
6.75
0.38
848.53
865.46
884.48
P-Value
0.03
0.01
0.05
0.006
0.01
0.05
Notes. Standard errors, clustered at the city level (except column 7), are in parentheses. P-values are extracted from the wild bootstrap procedure with city-
level clustering. All regressions include city and birth-region-by-birth-year fixed effects. Individual controls include dummies for race and ethnicity. Family
controls include maternal literacy dummy, paternal literacy dummy, maternal labor force status dummy, paternal labor force status dummy, paternal
socioeconomic score dummies, and a series of missing indicators for missing values of each variable. City controls include average share of homeowners,
average occupational income score, share of white-collar occupation, share of farmers, share of other occupation, literacy rate, and share of married.
*** p<0.01, ** p<0.05, * p<0.1
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Table 5 - Exploring Mechanism Channels
Outcomes and Samples:
1950-70 Census Data
DMF-Enlistment Data
Years of
Schooling
Education
High
School
Education
12 years
Socioeconomic
Score
Total
Family
Income
Log Total
Family
Income
Log AGCT
Log Height
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
Exposure to
Water
Filtration
.29***
-.037**
-.026
1.84***
2603.0
.03
.014
.016
(.10)
(.013)
(.018)
(.65)
(1580.3)
(.02)
(.008)
(.008)
Observations
245879
245879
245879
234773
235625
233920
33139
33139
R-squared
.27
.20
.11
.12
.09
.12
.02
.85
Mean DV
10.41
0.16
0.56
38.03
69308.46
10.97
4.94
0.98
P-Value
0.01
0.04
0.19
0.007
0.15
0.13
0.17
0.15
Notes. Standard errors, clustered on city, are in parentheses. P-values are extracted from the wild bootstrap procedure with city-level
clustering. All regressions include city fixed effects, birth-region-by-birth-year fixed effects, and city covariates. Regressions of columns 1-6
also include census year fixed effects. Individual controls include dummies for race and ethnicity. City controls include average share of
homeowners, average occupational income score, share of white-collar occupation, share of farmers, share of other occupation, literacy rate,
and share of married.
*** p<0.01, ** p<0.05, * p<0.1
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University of Chicago Press on behalf of the American Society of Health Economics.
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Figures
Figure 1 - Water Filtration Year across Cities in the Final Sample
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Notes. Point estimates and 95 percent confidence intervals, extracted from wild bootstrap procedure with city-level
clustering, are reported. All regressions include city and birth-region-by-birth-year fixed effects. Individual
controls include dummies for race and ethnicity. Family controls include maternal literacy dummy, paternal literacy
dummy, maternal labor force status dummy, paternal labor force status dummy, paternal socioeconomic score
dummies, and a series of missing indicator for missing values of each variable. City controls include average share
of homeowners, average occupational income score, share of white-collar occupation, share of farmers, share of
other occupation, literacy rate, and share of married.
Figure 2 - Exposure to Water Filtration across Different Ages and Later-Life Longevity
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Notes. Point estimates and 95 percent confidence intervals, extracted from wild bootstrap procedure with city-level
clustering, are reported. All regressions include city and birth-region-by-birth-year fixed effects.
Figure 3 - Exposure to Water Filtration across Different Ages and Observable Individual/Family
Characteristics
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Notes. Point estimates and 95 percent confidence intervals, extracted from wild bootstrap procedure with city-level
clustering, are reported. All regressions include city and birth-region-by-birth-year fixed effects.
Figure 4 - Exposure to Water Filtration across Different Ages and Observable Individual/Family
Characteristics
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Notes. Point estimates and 95 percent confidence intervals, extracted from wild bootstrap procedure with city-level
clustering, are reported. All regressions include city and birth-region-by-birth-year fixed effects.
Figure 5 - Exposure to Water Filtration across Different Ages and Observable Individual/Family
Characteristics
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1
Appendix
Table of Contents
Appendix A ........................................................................................................................... 48
Appendix B ........................................................................................................................... 49
Appendix C ........................................................................................................................... 51
Appendix D ........................................................................................................................... 61
Appendix E ........................................................................................................................... 63
Appendix F............................................................................................................................ 65
Appendix G ........................................................................................................................... 67
Appendix H ........................................................................................................................... 69
Appendix I ............................................................................................................................ 71
Appendix J ............................................................................................................................ 73
Appendix K ........................................................................................................................... 80
Appendix L ........................................................................................................................... 83
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2
Appendix A
Appendix Table A-1 - List of Cities and Year of Water Filtration
City
Year of Water Filtration
Providence, RI
1904
Indianapolis, IN
1904
Washington, DC
1905
Philadelphia, PA
1906
Cincinnati, OH
1907
Pittsburgh, PA
1908
Louisville, KY
1909
New Orleans, LA
1909
Minneapolis, MN
1913
Baltimore, MD
1915
St. Louis, MO
1915
Cleveland, OH
1918
St. Paul, MN
1923
Detroit, MI
1923
Buffalo, NY
1926
Kansas City, MO
1928
Milwaukee, WI
1939
Rochester, NY
Post-1940
Memphis, TN
Post-1940
Chicago, IL
Post-1940
San Francisco, CA
Post-1940
Boston, MA
Post-1940
Newark, NJ
Post-1940
New York, NY
Post-1940
Jersey City, NJ
Post-1940
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3
Appendix B
In the main results, we evaluated the effects of the share of childhood exposure up to age
15. Recall that we limit the sample to those born 15 years pre- and post-waterwork. Therefore, our
childhood ages end at 15 years. In Appendix Table B-1, we show the effects of the share of
exposure between birth and age 𝑧, where 𝑧 ∈{1,5,10,14}. We observe increases in magnitude as
we include more childhood ages. This is expected as all ages are treated although the effects are
more pronounced for earlier ages of life.
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4
Appendix Table B-1 - Exploring the Robustness across Age Thresholds for Childhood Exposure
Outcomes: Age at Death (Months)
𝑍=1 Year
𝑍=5 Years
𝑍=10 Years
𝑍=14 Years
(1)
(2)
(3)
(4)
Share of Childhood
Up to Age 𝑍
Exposed to Water
Filtration
1.87**
2.35**
3.16***
3.45***
(.53)
(.68)
(.61)
(.75)
Observations
338742
338742
338742
338742
R-squared
.38
.38
.38
.38
Mean DV
848.53
848.53
848.53
848.53
P-Value
0.04
0.04
0.009
0.008
Notes. Standard errors, clustered on city, are in parentheses. P-values are extracted from the wild bootstrap procedure with city-level clustering. All regressions include city
fixed effects, birth-year-by-birth-region fixed effects, individual controls, family controls, and city-level covariates. Individual controls include dummies for race and
ethnicity. Family controls include maternal literacy dummy, paternal literacy dummy, maternal labor force status dummy, paternal labor force status dummy, paternal
socioeconomic score dummies, and a series of missing indicators for missing values of each variable. City controls include average share of homeowners, average
occupational income score, share of white-collar occupation, share of farmers, share of other occupation, literacy rate, and share of married.
*** p<0.01, ** p<0.05, * p<0.1
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University of Chicago Press on behalf of the American Society of Health Economics.
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5
Appendix C
Ambitious public projects such as establishing water filtration stations could mirror
changes in political environment and economic conditions and may be followed by changes in
other public expenditures. For instance, public legislatures could allocate funds for public
education in addition to establishing water treatment facilities. In that case, the results might partly
incorporate the influences of improvements in public education, considering the literature that
documents the education longevity relationship. Similarly, public authorities might consider public
health interventions as substitutes and reallocate funds from other health expenditures toward
improving water quality.
For a subset of the sample years, we have information on state-level education expenditure
per capita and the number of doctors per capita (both extracted from Kose et al. (2021)). We then
examine changes in these outcomes in different years relative to the city-specific year of water
filtration, conditional on fixed effects and covariates. To ease interpretation and cross-panel
comparison, we standardize these outcomes with respect to their mean and standard deviation over
the sample period. These results are reported in the two panels of Appendix Figure C-1. The results
do not reveal any significant changes in many years prior to and after water filtration.
Another concern is that the public health interventions related to water quality were
accompanied by other interventions, such as chlorination of water and sewage treatment. In
Appendix Figure C-2 through Appendix Figure C-6, we show the year of different public health
interventions relative to the year of water filtration across cities in the final sample. In most cases,
water filtration occurs after water chlorination. Therefore, one argument is that the positive impacts
we observe in the paper are due to the combined benefits of filtration and chlorination. However,
we do not observe a significant association of water filtration status with chlorination of water
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once we examine their correlation using an event study framework with city and region-by-year
fixed effects (top left panel of Appendix Figure C-7). This is also true for sewage treatment and
implementation of bacteriological standards for milk (top right and bottom left panels of Appendix
Figure C-7). We do observe a lower probability of any major water project after water filtration
(bottom right panel of Appendix Figure C-7).
Further, we examine the influence of these other public health interventions on longevity.
In so doing, we generate dummies that equal one if a city has initiated any of these interventions.
We then merge with the final sample based on year and city of birth and implement regressions
similar to equation 1. The results are reported in columns 1-3 of Appendix Table C-1. We observe
a 0.9-month rise in longevity due to early-life exposure to water chlorination. However, the
estimated effect is insignificant at 10 percent level (column 1). For the sewage treatment, we
observe a significant increase in longevity of about 2 months (column 2). However, when we
include these interventions in the presence of water filtration (column 4), we observe a larger
coefficient for water filtration. The respective coefficient of other interventions becomes
statistically insignificant, suggesting that the main benefits of waterworks arise from water
filtration. We should note that previous studies suggest that among several public health
interventions during the early 20th century in the US, water filtration was the most successful, with
significant health benefits (Anderson, Charles, & Rees, 2022; Costa, 2015; Cutler & Miller, 2005).
Despite the evidence in column 4, we should acknowledge that our sample covers only 25 cities
in a specific timeframe in the US. The US currently has 150,000 public water systems. Therefore,
our sample may not fully reveal the benefits of other interventions including chlorination of water.
Specifically, other interventions such as chlorination of water have been documented to be quite
beneficial for health outcomes in other settings (Nadimpalli et al. 2022).
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Notes. Point estimates and 95 percent confidence intervals, extracted from
wild bootstrap procedure with city-level clustering, are reported. Regressions
include city and region-by-year fixed effects. Regressions are weighted
using city-level population.
Appendix Figure C-1 - Event-Study Tests to Examine the Evolution of
Public Expenditure pre/post Water Filtration
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Appendix Figure C-2 - The Evolution of Water Filtration along with Other Public Health Interventions in the
Cities in the Final Sample
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Appendix Figure C-3 - The Evolution of Water Filtration along with Other Public Health Interventions in the
Cities in the Final Sample
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Appendix Figure C-4 - The Evolution of Water Filtration along with Other Public Health Interventions in the
Cities in the Final Sample
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Appendix Figure C-5 - The Evolution of Water Filtration along with Other Public Health Interventions in the
Cities in the Final Sample
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Appendix Figure C-6 - The Evolution of Water Filtration along with Other Public Health Interventions in the
Cities in the Final Sample
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Notes. Point estimates and 95 percent confidence intervals, extracted from wild bootstrap procedure with city-
level clustering, are reported. Regressions include city and region-by-year fixed effects. Regressions are
weighted using city-level population.
Appendix Figure C-2 - Event-Study Tests to Examine the Evolution of City-Level Public Health Interventions
pre/post Water Filtration
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Appendix Table C-1 - Examining Other Public Health Interventions
Outcome: Age at Death (Months)
(1)
(2)
(3)
(4)
Water Filtration
2.57
(1.22)
[0.15]
Chlorination of
Water
.85
.23
(.74)
(.72)
[0.31]
[0.77]
Sewage Treatment
or Diversion
2.02
1.69
(1.10)
(1.22)
[0.14]
[0.31]
Bacteriological
Standard for Milk
.74
.56
(.68)
(.68)
[0.34]
[0.44]
Observations
338742
338742
338742
338742
R-squared
.35
.35
.35
.35
Mean DV
867.24
867.24
867.24
867.24
Notes. Standard errors, clustered on city, are in parentheses. P-values are extracted from the wild bootstrap
procedure with city-level clustering and are reported in brackets. All regressions include city fixed effects, birth-
year-by-birth-region fixed effects, individual controls, family controls, and city-level covariates. Individual controls
include dummies for race and ethnicity. Family controls include maternal literacy dummy, paternal literacy dummy,
maternal labor force status dummy, paternal labor force status dummy, paternal socioeconomic score dummies, and
a series of missing indicators for missing values of each variable. City controls include average share of
homeowners, average occupational income score, share of white-collar occupation, share of farmers, share of other
occupation, literacy rate, and share of married.
*** p<0.01, ** p<0.05, * p<0.1
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15
Appendix D
The final sample of the paper, constructed from the DMF data, exclusively focused on male
individuals. In this appendix, we employ the Berkeley Unified Numident Mortality Database
(BUNMD) from the Censoc project to examine the effects across both genders. The advantage of
the BUNMD data is that it covers both genders. Although this data covers a small portion of pre-
1975 deaths and ends in 2007 (hence more death years compared with the DMF 1975-2005), the
death coverage is relatively thin and unreliable for the years prior to 1988. Moreover, the data is
not linked to the 1940 census. On the other hand, the BUNMD data reports county/city-of-birth
directly and relieves us from the measurement errors caused by cross-census linking. We replicate
the main results using BUNMD data and report them in Appendix Table D-1. In column 1, we
observe an insignificant increase in longevity of about 1.6 months. When we focus on male
individuals in column 2, we observe a significant change of about 3.1 months, an effect size that
is quite comparable to the main results of the paper. For the female subsample in column 3, we
observe a relatively small and insignificant coefficient. Therefore, we argue that the main benefits
appear to be for male individuals only.
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Appendix Table D-1 - Replicating the Main Results Using BUNMD Data
Outcomes: Age at Death (Months)
Full Sample
Males
Females
(1)
(2)
(3)
Exposure to Water
Filtration
1.61
3.05
.68
(1.47)
(1.65)
(1.71)
Observations
3480529
1702463
1777755
R-squared
.40
.32
.44
Mean DV
928.75
906.001
950.55
P-Value
0.35
0.18
0.74
Notes. Standard errors, clustered on city, are in parentheses. P-values are extracted from the wild bootstrap
procedure with city-level clustering. All regressions include city fixed effects, birth-year-by-birth-region fixed
effects, individual controls, family controls, and city-level covariates. Individual controls include dummies for race
and ethnicity. Family controls include maternal literacy dummy, paternal literacy dummy, maternal labor force
status dummy, paternal labor force status dummy, paternal socioeconomic score dummies, and a series of missing
indicators for missing values of each variable. City controls include average share of homeowners, average
occupational income score, share of white-collar occupation, share of farmers, share of other occupation, literacy
rate, and share of married.
*** p<0.01, ** p<0.05, * p<0.1
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17
Appendix E
In the main results of the paper, we restrict the sample to cohorts that were born 15 years
before and 15 years after city-specific water filtration year. In panel A of Appendix Table E-1, we
remove this restriction and replicate the main results. The effect size of column 3 remains quite
comparable to the main results of Table 2. In panel B, we make the stricter balancing window
restriction, i.e., restricting to cohorts born 12 years before and after city-specific water filtration
year. The fully parameterized regression of column 3 suggests a slightly larger effect size.
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Appendix Table E-1 - Sensitivity of the Results to the Balancing Window Restriction
Outcomes: Age at Death (Months)
(1)
(2)
(3)
Panel A. No Balancing Window Restriction
Exposure to Water
Filtration
2.40
2.35
2.92***
(1.45)
(1.34)
(.82)
Observations
396339
396339
396330
R-squared
.35
.35
.35
Mean DV
870.39
870.39
870.39
P-Value
0.13
0.10
0.004
Panel B. 12-Years Balancing Window Restriction
Exposure to Water
Filtration
3.90**
3.50*
4.04**
(1.60)
(1.53)
(1.11)
Observations
318636
318636
318620
R-squared
.35
.35
.35
Mean DV
869.38
869.38
869.38
P-Value
0.03
0.05
0.02
City FE
✓
✓
✓
Birth Year FE
✓
✓
✓
Individual Controls
✓
✓
✓
Family Controls
✓
✓
✓
City Controls
✓
✓
Region-by-Cohort FE
✓
Notes. Standard errors, clustered on city, are in parentheses. P-values are extracted from the wild bootstrap
procedure with city-level clustering. Individual controls include dummies for race and ethnicity. Family controls
include maternal literacy dummy, paternal literacy dummy, maternal labor force status dummy, paternal labor force
status dummy, paternal socioeconomic score dummies, and a series of missing indicators for missing values of each
variable. City controls include average share of homeowners, average occupational income score, share of white-
collar occupation, share of farmers, share of other occupation, literacy rate, and share of married.
*** p<0.01, ** p<0.05, * p<0.1
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19
Appendix F
The age profile of individuals in the final sample varies between 35 and 104. In this
appendix, we replicate the analysis using the sample of individuals who survived up to ages 50,
55, 60, 65, and 70. These estimates are reported in Appendix Table F-1. Although the estimated
coefficient sizes are smaller than that of the main results, they are fairly robust across different
subsamples in consecutive columns. We should note that older individuals in the subsamples
represent early treated cities. The fact that the inclusion of individuals who died earlier (before age
50) boosts the magnitude of the coefficients may imply that the effects are slightly larger for later
cohorts and that survival of earlier cohorts beyond the life expectancy of those cohorts only pushes
the coefficients downward.
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Appendix Table F-1 - Replicating the Main Results Using Different Subsamples based on Survival Age
Outcomes: Age at Death (Months), Conditional on Survival up to Age:
50
55
60
65
70
(1)
(2)
(3)
(4)
(5)
Exposure to Water
Filtration
2.28
2.36*
1.80
2.35*
2.29
(1.11)
(.96)
(1.11)
(1.38)
(1.15)
Observations
328859
316598
292413
249347
192493
R-squared
.28
.25
.21
.17
.17
Mean DV
876.70
885.62
900.56
923.95
953.91
P-Value
0.10
0.07
0.18
0.05
0.11
Notes. Standard errors, clustered on city, are in parentheses. P-values are extracted from the wild bootstrap procedure with city-level clustering. All regressions
include city fixed effects, birth-year-by-birth-region fixed effects, individual controls, family controls, and city-level covariates. Individual controls include
dummies for race and ethnicity. Family controls include maternal literacy dummy, paternal literacy dummy, maternal labor force status dummy, paternal labor
force status dummy, paternal socioeconomic score dummies, and a series of missing indicators for missing values of each variable. City controls include average
share of homeowners, average occupational income score, share of white-collar occupation, share of farmers, share of other occupation, literacy rate, and share
of married.
*** p<0.01, ** p<0.05, * p<0.1
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21
Appendix G
One potential heterogeneity in the results is that improvements in water quality could be
more beneficial in areas with a more severe disease environment. Infant mortality rates (IMR) are
highly correlated with the availability of sanitation, water quality, healthcare access, and general
disease environment. Indeed, several studies use IMR as a proxy for the general disease
environment (Case and Paxson 2009; Almond, Currie, and Herrmann 2012). In columns 1 and 2
of Appendix Table G-1, we examine the source of heterogeneity by replicating the main results in
the subsamples based on city-cohort-specific IMR. The estimated coefficient of the high IMR
subsample is about twice the size of the low IMR subsample.
In section 6, we argued that human capital and socioeconomic status are potential pathways
between early life exposure to water quality and later life longevity. Therefore, one could expect
to observe larger impacts on the same mediatory outcomes in high IMR versus low IMR
subsamples. Using the same sample and method as in section 6, we replicate the results on years
of schooling and socioeconomic index for high and low IMR subsamples and report them in
columns 3-6 of Appendix Table G-1. Relative to the low IMR subsample, the high IMR subsample
reveals a slightly larger and statistically significant impact on years of schooling. While we observe
positive, large, and significant impacts on the socioeconomic index for the high IMR subsample,
the coefficient of the low IMR subsample points to negative and insignificant effects on the
socioeconomic index. Overall, the results of this appendix support the notion that improvements
in human capital and socioeconomic status during adulthood are pathways of the main findings of
the paper.
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Appendix Table G-1 - Heterogeneity in the Results Based on Birth-City-Level Infant Mortality Rates
Data, Outcome, and Subsample:
DMF
Age-at-Death
High IMR
DMF
Age-at-Death
Low IMR
Census 1950-1970
Schooling
High IMR
Census 1950-1970
Schooling
Low IMR
Census 1950-1970
SEI
High IMR
Census 1950-1970
SEI
Low IMR
(1)
(2)
(3)
(4)
(5)
(6)
Exposure to Water
Filtration
3.76
1.93
.25***
.21
1.85***
-1.37
(.71)
(1.27)
(.08)
(.33)
(.52)
(1.29)
Observations
170909
167794
158445
87434
151631
83142
R-squared
.38
.39
.31
.17
.12
.12
Mean DV
844.02
854.21
10.40
10.43
38.48
37.21
P-Value
0.16
0.41
0.00
0.65
0.00
0.49
Notes. Standard errors, clustered on city, are in parentheses. P-values are extracted from the wild bootstrap procedure with city-level clustering. Regressions of columns 1-2 include city
fixed effects, birth-year-by-birth-region fixed effects, individual controls, family controls, and city-level covariates. Individual controls include dummies for race and ethnicity. Family
controls include maternal literacy dummy, paternal literacy dummy, maternal labor force status dummy, paternal labor force status dummy, paternal socioeconomic score dummies, and
a series of missing indicators for missing values of each variable. City controls include average share of homeowners, average occupational income score, share of white-collar occupation,
share of farmers, share of other occupation, literacy rate, and share of married. Regressions of columns 3-6 include city fixed effects, birth-year-by-birth-region fixed effects, individual
controls, and city-level covariates. IMR stands for infant mortality rate and is calculated based on birth-city-birth-year-level rate of infant mortality. SEI stands for socioeconomic index.
*** p<0.01, ** p<0.05, * p<0.1
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23
Appendix H
One concern in the main results is the migration of individuals post-water filtration. For
these migrations to affect our estimates, they should correlate with exposure to water filtration.
We can empirically examine the association between migration and exposure to water filtration
using the full count 1940 census. We link the full count census individuals in the cities covered in
our final sample and who were born between 1900-1940 to 1910, 1920, and 1930 full count
censuses. For the subsample of linked individuals, we can observe whether they changed city (or
state) between each census year (1910-1930) and 1940. We then use the migration status as the
outcome in regressions similar to equation 1. The results are reported in Appendix Table H-1. We
do not observe a significant association between exposure to water filtration during childhood and
the probability of migration from 1910-city, 1920-city, and 1930-city to 1940-city (columns 1-3).
We do observe a significant coefficient for across-state migration between 1920 and 1940.
However, this is not consistent for across states migration between 1910 to 1940 and 1930 to 1940
years.
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Appendix Table H-1 - Exposure to Water Filtration and Cross-Census Migration
Outcomes:
Changed city
between 1910 and
1940
Changed city
between 1920 and
1940
Changed city
between 1930 and
1940
Changed state
between 1910 and
1940
Changed state
between 1920 and
1940
Changed state
between 1930
and 1940
(1)
(2)
(3)
(4)
(5)
(6)
Exposure to Water
Filtration
.05827
.0009
-.00575
.03258
.03744***
.01535
(.04778)
(.0253)
(.02397)
(.02841)
(.01156)
(.01529)
Observations
69114
265064
393467
69114
265064
393467
R-squared
.04241
.03674
.03363
.02303
.02856
.02787
Mean DV
0.396
0.315
0.207
0.184
0.134
0.079
P-Value
0.185
0.975
0.847
0.242
0.001
0.354
Notes. Standard errors, clustered on city, are in parentheses. P-values are extracted from the wild bootstrap procedure with city-level clustering. All regressions
include city fixed effects, birth-year-by-birth-region fixed effects, individual controls, family controls, and city-level covariates. Individual controls include
dummies for race and ethnicity. Family controls include maternal literacy dummy, paternal literacy dummy, maternal labor force status dummy, paternal labor
force status dummy, paternal socioeconomic score dummies, and a series of missing indicators for missing values of each variable. City controls include average
share of homeowners, average occupational income score, share of white-collar occupation, share of farmers, share of other occupation, literacy rate, and share
of married.
*** p<0.01, ** p<0.05, * p<0.1
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25
Appendix I
The main difference-in-difference coefficient of the main results aggregates the impacts
across childhood ages. The general pattern of Figure 2 suggests larger impacts for in-utero and
early-life exposures. In this appendix, we disaggregate the exposure measure across different ages
to be able to better isolate critical ages. Specifically, we are low for different ages at exposure to
compete with each other. In so doing, we define dummy variables capturing exposure during in
utero and ages 0, between ages 1-4, and between ages 5-9. The age group 10-15 (and those in
treated cities) serves as the contrast group. The results are reported in Appendix Table I-1. In
column 3, we observe a monotonic pattern across coefficients: the earlier in life the exposure, the
higher the magnitude of the impact. Further, the effects become comparably small in magnitude
and statistically insignificant for the age group 5-9.
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26
Appendix Table I-1 - Exploring the Heterogeneity in the Effects of Exposure across Different Ages
Outcomes: Age at Death (Months)
(1)
(2)
(3)
Exposure to Water
Filtration in-Utero and
Age 0
1.674
2.606*
3.334**
(.8025)
(1.093)
(.836)
{0.150}
{0.070}
{0.012}
Exposure to Water
Filtration Ages 1-4
1.966
2.628***
(.992)
(.732)
{0.116}
{0.002}
Exposure to Water
Filtration Ages 5-9
1.001
(.836)
{0.422}
Observations
338742
338742
338742
R-squared
.356
.356
.356
Notes. Standard errors, clustered on city, are in parentheses. P-values are extracted from the wild bootstrap
procedure with city-level clustering and reported in curly bracket. All regressions include city fixed effects, birth-
year-by-birth-region fixed effects, individual controls, family controls, and city-level covariates. Individual controls
include dummies for race and ethnicity. Family controls include maternal literacy dummy, paternal literacy dummy,
maternal labor force status dummy, paternal labor force status dummy, paternal socioeconomic score dummies,
and a series of missing indicators for missing values of each variable. City controls include average share of
homeowners, average occupational income score, share of white-collar occupation, share of farmers, share of other
occupation, literacy rate, and share of married.
*** p<0.01, ** p<0.05, * p<0.1
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27
Appendix J
One concern in the main results is the potential endogenous association of water filtration
with other state/city-level policy changes and sociodemographic transitions. In so doing, we use a
panel of city-by-year covariates and use city-level characteristics and policy changes as the
outcome. We execute event studies similar to equation 2 conditional on city and region-by-year
fixed effects. In these regressions, we use city-level population as weights and cluster standard
errors at the city level. We report confidence intervals based on wild bootstrap procedures with
city-level clustering. To enable comparison across regressions and figures, we standardize all
outcomes with respect to the variables’ mean and standard deviations in the final sample. The
results are reported in Appendix Figure J-1 through Appendix Figure J-5.
We do not find a robust and statistically significant association between water
implementation and state-wide prohibition reforms, share of dry counties in each state, suffrage
reform, poll tax policy change, state-level implementation of birth registration laws, state entrance
into birth registration area, and the presence of child labor and compulsory attendance laws
(Appendix Figure J-1 and Appendix Figure J-2). Almost all pre-trend and post-trend coefficients
are small in magnitude and statistically insignificant.
1
In the next set of figures, we explore differences in city-level sociodemographic and
socioeconomic characteristics across treated-control groups and over different years relative to the
public health reforms. We do not observe a discernible pre-trend and post-trend in various
outcomes, including the share of whites, blacks, people of other races, and immigrants (Appendix
1
Compulsory Attendance (CA) is a measure of state-imposed mandatory years of schooling and is calculated as the
largest of required years of schooling before dropping out and the difference between the minimum school-leaving
age and the maximum age at enrollment. Child Labor (CL) index measures the enforcement of age limitation for a
work permit and is the largest of years of education required for a work permit and the difference between the
minimum age for a work permit and the maximum age allowed for school enrollment. These measures are extracted
from Acemoglu & Angrist (2000) and are used in Appendix Figure J-2.
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Figure J-3); share of females, children less than 5 years old, married women, and literate people
(Appendix Figure J-4); average occupational income score, the share of homeowners, blue-collar
workers, and farmers (Appendix Figure J-5). These tests fail to provide robust, consistent, and
significant evidence that changes in the demographic and socioeconomic characteristics of the
cities could confound the estimates.
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29
Notes. Point estimates and 95 percent confidence intervals, extracted from wild bootstrap procedure with city-
level clustering, are reported. Regressions include city and region-by-year fixed effects. Regressions are
weighted using city-level population.
Appendix Figure J-1 - Event-Study Tests to Examine the Evolution of City Observables pre/post Water
Filtration
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Notes. Point estimates and 95 percent confidence intervals, extracted from wild bootstrap procedure with city-
level clustering, are reported. Regressions include city and region-by-year fixed effects. Regressions are
weighted using city-level population.
Appendix Figure J-2 - Event-Study Tests to Examine the Evolution of City Observables pre/post Water
Filtration
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31
Notes. Point estimates and 95 percent confidence intervals, extracted from wild bootstrap procedure with city-
level clustering, are reported. Regressions include city and region-by-year fixed effects. Regressions are
weighted using city-level population.
Appendix Figure J-3 - Event-Study Tests to Examine the Evolution of City Observables pre/post Water
Filtration
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32
Notes. Point estimates and 95 percent confidence intervals, extracted from wild bootstrap procedure with city-
level clustering, are reported. Regressions include city and region-by-year fixed effects. Regressions are
weighted using city-level population.
Appendix Figure J-4 - Event-Study Tests to Examine the Evolution of City Observables pre/post Water
Filtration
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33
Notes. Point estimates and 95 percent confidence intervals, extracted from wild bootstrap procedure with city-
level clustering, are reported. Regressions include city and region-by-year fixed effects. Regressions are
weighted using city-level population.
Appendix Figure J-5 - Event-Study Tests to Examine the Evolution of City Observables pre/post Water
Filtration
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Appendix K
In this appendix, we explain the procedure of cross-census linking and construction of the
final sample. We start with the full count 1940 census and link the records to DMF death records.
This leaves us with an initial linked sample size of roughly 7.7 million observations. We then
restrict the sample to individuals born between 1900-1940, reducing the sample to about 6.6
million observations. Next, we use cross-census linking rules to link individuals across historical
censuses 1900-1930. For cohorts born between 1900-1905, we use the following information from
the 1900 census: city, state, and parental information. Similarly, for cohorts born between 1906-
1910, 1911-1920, and 1921-1930 we use information from 1910, 1920, and 1930 censuses. In the
1940 census, we have information on county of residence in 1935. If the household did not move
from 1935 to 1940, the 1935 county is the same as the 1940 county. For cohorts born between
1931-1935, we use the information of 1935 county (and state) to assign the city of birth/childhood.
This is possible because for 24 cities out of 25 cities of the final sample, there is a 1-to-1 link
between city and county. Further, several counties within New York City can be mapped only to
New York City (the 25th city). Finally, for cohorts born between 1936-1940, we use information
from the 1940 census. We drop all individuals who are not linked and for whom we cannot infer
the city of birth/childhood as well as parental information.
These selections leave us with a sample size of about 2.4 million observations. The sample
contains 1,037 cities. Restricting the sample to 25 cities in the final sample for which we have
information on water filtration reduces its size by about 84%. We further restrict the sample to
cohorts born 15 years before and after the city-specific water filtration year (only for treated cities).
The final sample size covers roughly 338 thousand observations.
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Although the cross-census linking considerably reduces the sample size, the process
arguably limits measurement error in assigning the city of birth/childhood. In Appendix Table K-1,
we use the 1940 city as the city of birth/childhood and replicate the main results. We observe point
estimates that are 30 percent smaller in size than the main results, suggesting that measurement
errors likely result in coefficients that underestimate the true impacts.
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Appendix Table K-1 - Replicating the Main Results Using the 1940 City as City of Birth/Childhood
Outcomes: Age at Death (Months)
(1)
(2)
(3)
Exposure to Water
Filtration
1.44
1.40
2.18
(1.22)
(1.30)
(1.70)
Observations
996533
996533
996533
R-squared
.36
.36
.36
Mean DV
887.05
887.05
887.05
P-Value
0.24
0.33
0.28
City FE
✓
✓
✓
Birth Year FE
✓
✓
✓
Individual Controls
✓
✓
✓
Family Controls
✓
✓
✓
City Controls
✓
✓
Region-by-Cohort FE
✓
Notes. Standard errors, clustered on city, are in parentheses. P-values are extracted from the wild bootstrap
procedure with city-level clustering. Individual controls include dummies for race and ethnicity. Family controls
include maternal literacy dummy, paternal literacy dummy, maternal labor force status dummy, paternal labor force
status dummy, paternal socioeconomic score dummies, and a series of missing indicators for missing values of each
variable. City controls include average share of homeowners, average occupational income score, share of white-
collar occupation, share of farmers, share of other occupation, literacy rate, and share of married.
*** p<0.01, ** p<0.05, * p<0.1
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Appendix L
One concern regarding the exogeneity assumption pertains to parental fertility response to
city-wide public health infrastructure improvements. For instance, if water filtration had an evident
impact on infant mortality, parents may observe improvements in their children's survival and be
encouraged to increase fertility. Similarly, they may reduce their fertility as the target number of
children could be attained by fewer births in the presence of lower child mortality rates (Palloni
and Rafalimanana 1999; Sandberg 2016). Moreover, the fertility decision could also be correlated
with other sociodemographic characteristics of parents, which are among the determinants of their
children’s later-life longevity.
To address these concerns, we use limited natality and mortality data available for a subset
of cities and counties in the data for the years 1915-1940 extracted from Bailey et al. (2016). The
data reports the infant mortality and birth rates at the city-year level. We merge this data with water
filtration data and implement regressions that include city and year fixed effects. First, we explore
the effects on infant mortality rates. These results are reported in column 1 of Appendix Table L-1.
Water filtration results in roughly 6.3 fewer infant deaths per 100,000 live births, equivalent to a
9.8 percent reduction from the outcome’s mean.
2
However, this finding is sensitive to the
functional form and becomes insignificant when we use the log infant mortality rate as the outcome
(column 2). Next, we assess the associations with the birth rate per 1,000 women and log birth rate
2
There are two reasons that our findings on mortality rate is different than those reported by Anderson, Charles, &
Rees (2022), i.e., roughly 11% reduction. First, they include a city-specific time trend while we do not. Including unit-
specific trends may over-control for time-varying treatment effects and has been a controversial issue in the literature
(Lee and Solon 2011; Meer and West 2016; Neumark, Salas, and Wascher 2014; Gruber and Frakes 2006; Chou,
Grossman, and Saffer 2006; Goodman-Bacon 2021). Second, since the main purpose of this section is to evaluate
fertility response, we use natality records from a data source that contains birth rate information starting from 1915.
To have a similar panel with natality records, we also use mortality during the same period (i.e., 1915-1940). Indeed,
when we use the replication data of Anderson, Charles, & Rees (2022), limit the sample to 1915-1940 years, and
remove the city-trend, we reach almost identical effects as columns 1-2 of Appendix Table L-1, both for level and log
of infant mortality rate.
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(columns 3-4). The estimated coefficient suggests small and statistically insignificant reductions
in the birth rate, which limits further interpretations. Overall, while we find some evidence for
improvements in infants’ health, we fail to observe a discernible fertility response.
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39
Appendix Table L-1 - Effects on Infant Mortality and Fertility Rates
Outcomes:
Infant Mortality
Rate
Log Infant
Mortality Rate
Birth Rate
Log Birth Rate
(1)
(2)
(3)
(4)
Exposure to Water
Filtration
-6.389**
-.032
-2.539
-.024
(2.414)
(.041)
(1.859)
(.032)
Observations
559
559
559
559
R-squared
.976
.977
.969
.979
Mean DV
63.997
4.103
37.580
3.630
P-Value
0.024
0.396
0.154
0.447
Notes. Standard errors, clustered on city, are in parentheses. P-values are extracted from the wild bootstrap
procedure with city-level clustering. Regressions include city and region-by-year fixed effects. Regressions also
include city covariates. City controls include average share of homeowners, average occupational income score,
share of white-collar occupation, share of farmers, share of other occupation, literacy rate, and share of married.
*** p<0.01, ** p<0.05, * p<0.1
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Journal of Health Economics, published by The University of Chicago Press on behalf of the American Society of Health Economics.
Include the DOI when citing or quoting: https://doi.org/10.1086/734081. Copyright 2024 American Society of Health Economics.