Article

Maybe Next Month? Temperature Shocks, Climate Change, and Dynamic Adjustments in Birth Rates

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Dynamic adjustments could be a useful strategy for mitigating the costs of acute environmental shocks when timing is not a strictly binding constraint. To investigate whether such adjustments could apply to fertility, we estimate the effects of temperature shocks on birth rates in the United States between 1931 and 2010. Our innovative approach allows for presumably random variation in the distribution of daily temperatures to affect birth rates up to 24 months into the future. We find that additional days above 80 °F cause a large decline in birth rates approximately 8 to 10 months later. The initial decline is followed by a partial rebound in births over the next few months implying that populations can mitigate the fertility cost of temperature shocks by shifting conception month. This dynamic adjustment helps explain the observed decline in birth rates during the spring and subsequent increase during the summer. The lack of a full rebound suggests that increased temperatures due to climate change may reduce population growth rates in the coming century. As an added cost, climate change will shift even more births to the summer months when third trimester exposure to dangerously high temperatures increases. Based on our analysis of historical changes in the temperature-fertility relationship, we conclude air conditioning could be used to substantially offset the fertility costs of climate change.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Empirically, fertility has been observed to decline during periods of hardship, such as conflict, disease exposure, and economic decline (Agadjanian and Prata 2002;Lindstrom and Berhanu 1999;Sobotka et al. 2011;Terceira et al. 2003), but to increase following the eradication of some forms of disease, such as malaria (Lucas 2013). Nevertheless, interpreting the alignment of demographic rates and contextual health threats as evidence of strategic change in reproductive behavior is difficult (Alam and Portner 2018;Barreca et al. 2018;Kim and Prskawetz 2010;National Research Council 2004). In many cases, factors that increase the costs and/or risks of childbearing also affect other proximate determinants of fertility. ...
... Disaster, conflict, or epidemic may result in family separation and an accompanying reduction in coital frequency. Health threats may also reduce biological fecundity (e.g., Barreca et al. 2018;Terceira et al. 2003); changes in exposure to nutrition, infection, and multiple forms of physiological stress have effects on organ systems centrally involved in establishing a pregnancy and carrying it to term (Arck et al. 2008;Larsen et al. 2013). In addition to these alternative explanations, the standard threats to interpretation in observational research are also relevant. ...
... Most theoretical models of human fertility predict the adjustment of reproductive behavior in response to changing circumstances (Hotz et al. 1997;Johnson-Hanks et al. 2011;Trinitapoli and Yeatman 2018). Decades of demographic research have documented examples of changes in fertility rates in the wake of major events, including macroeconomic change, violence and conflict, environmental change, mortality shocks, and shifts in the disease landscape (Agadjanian and Prata 2002;Barreca et al. 2018;Bleakley and Lange 2009;Heuveline and Poch 2007;Lindstrom and Berhanu 1999;McCord et al. 2017). In a few cases, evidence on accompanying changes to stated fertility intentions (e.g., Agadjanian and Prata 2002) suggests that some people may try to adjust fertility timing to align births with more favorable circumstances. ...
Article
Zika virus epidemics have potential large-scale population effects. Controlled studies of mice and nonhuman primates indicate that Zika affects fecundity, raising concerns about miscarriage in human populations. In regions of Brazil, Zika risk peaked months before residents learned about the epidemic and its relation to congenital anomalies. This spatiotemporal variation supports analysis of both biological effects of Zika infection on fertility and the effects of learning about Zika risk on reproductive behavior. Causal inference techniques used with vital statistics indicate that the epidemic caused reductions in birth cohort size of approximately one-quarter 18 months after Zika infection risk peaked but 10 months after public health messages advocated childbearing delay. The evidence is consistent with small but not statistically detectable biological reductions in fecundity, as well as large strategic changes in reproductive behavior to temporally align childbearing with reduced risk to infant health. The behavioral effects are larger for more-educated and older women, which may reflect facilitated access to information and to family planning services within high-risk, mosquito-infested urban locations as well as perceptions about the opportunity costs of risks to pregnancy and infant survival.
... Considering the different structures of these responses is important for understanding the response of social systems to different types of climatic factors. For example, it has been shown that extreme heat reduces the number of children born exactly 9 months later but elevates births 11 to 13 months later, as some of the successful conceptions that would have occurred during the hot period, but did not, end up occurring in the near future (38). In these cases, where climatic events simply displace the timing of societal outcomes (a pattern illustrated in Fig. 2G), changes in the distribution of climatic events may have a smaller net effect than one would predict if this dynamic response were not accounted for. ...
... (B) Tropical cyclones increase female infant deaths but with a delayed effect that grows rapidly roughly a year after exposure (49). (C) Birth rates in the United States fall 8 to 10 months after a hot day, but this decline is partially compensated for by an increase during months 11 to 13 (38). (D) GDP in countries exposed to tropical cyclones falls gradually but persistently during the 15 years following exposure (116). ...
... New findings also suggest that overall population growth may be directly influenced by the climate through altering sexual behavior or fertility rates. Birth rates are abnormally lower 9 months after extreme heat events in both sub-Saharan Africa (69) and the United States (38) (Fig. 4C), although identifying the mechanism driving this effect is challenging. Remarkably, these results appear to explain a large fraction of birth seasonality across climates, and projections for the United States suggest that warming will reduce birth rates 3% (38). ...
Article
BACKGROUND For centuries, thinkers have considered whether and how climatic conditions influence the nature of societies and the performance of economies. A multidisciplinary renaissance of quantitative empirical research has begun to illuminate key linkages in the coupling of these complex natural and human systems, uncovering notable effects of climate on health, agriculture, economics, conflict, migration, and demographics. ADVANCES Past scholars of climate-society interactions were limited to theorizing on the basis of anecdotal evidence; advances in computing, data availability, and study design now allow researchers to draw generalizable causal inferences tying climatic events to social outcomes. This endeavor has demonstrated that a range of climate factors have substantial influence on societies and economies, both past and present, with important implications for the future. Temperature, in particular, exerts remarkable influence over human systems at many social scales; heat induces mortality, has lasting impact on fetuses and infants, and incites aggression and violence while lowering human productivity. High temperatures also damage crops, inflate electricity demand, and may trigger population movements within and across national borders. Tropical cyclones cause mortality, damage assets, and reduce economic output for long periods. Precipitation extremes harm economies and populations predominately in agriculturally dependent settings. These effects are often quantitatively substantial; for example, we compute that temperature depresses current U.S. maize yields roughly 48%, warming trends since 1980 elevated conflict risk in Africa by 11%, and future warming may slow global economic growth rates by 0.28 percentage points year ⁻¹ . Much research aims to forecast impacts of future climate change, but we point out that society may also benefit from attending to ongoing impacts of climate in the present, because current climatic conditions impose economic and social burdens on populations today that rival in magnitude the projected end-of-century impacts of climate change. For instance, we calculate that current temperature climatologies slow global economic growth roughly 0.25 percentage points year ⁻¹ , comparable to the additional slowing of 0.28 percentage points year ⁻¹ projected from future warming. Both current and future losses can theoretically be avoided if populations adapt to fully insulate themselves from the climate—why this has not already occurred everywhere remains a critical open question. For example, clear patterns of adaptation in health impacts and in response to tropical cyclones contrast strongly with limited adaptation in agricultural and macroeconomic responses to temperature. Although some theories suggest these various levels of adaptation ought to be economically optimal, in the sense that costs of additional adaptive actions should exactly balance the benefits of avoided climate-related losses, there is no evidence that allows us to determine how closely observed “adaptation gaps” reflect optimal investments or constrained suboptimal adaptation that should be addressed through policy. OUTLOOK Recent findings provide insight into the historical evolution of the global economy; they should inform how we respond to modern climatic conditions, and they can guide how we understand the consequences of future climate changes. Although climate is clearly not the only factor that affects social and economic outcomes, new quantitative measurements reveal that it is a major factor, often with first-order consequences. Research over the coming decade will seek to understand the numerous mechanisms that drive these effects, with the hope that policy may interfere with the most damaging pathways of influence. Both current and future generations will benefit from near-term investigations. “Cracking the code” on when, where, and why adaptation is or is not successful will generate major social benefits today and in the future. In addition, calculations used to design global climate change policies require as input “damage functions” that describe how social and economic losses accrue under different climatic conditions, essential elements that now can (and should) be calibrated to real-world relationships. Designing effective, efficient, and fair policies to manage anthropogenic climate change requires that we possess a quantitative grasp of how different investments today may affect economic and social possibilities in the future. Two globes depict two possible futures for how the climate might change and how those changes are likely to affect humanity, based on recent empirical findings Base colors are temperature change under “Business as usual” (left, RCP 8.5) and “stringent emissions mitigation” (right, RCP 2.6). Overlaid are composite satellite images of nighttime lights with rescaled intensity reflecting changes in economic productivity in each climate scenario.
... The summer effect dominates the fall effect in our recent sample (post-1990), leading to a negative net economic effect of rising temperatures. This implies that the U.S. economy is still sensitive to temperature increases, despite the progressive adoption of adaptive technologies such as air conditioning (Barreca, Deschenes, and Guldi 2015). We also document that the temperature effects are particularly strong in states with relatively higher summer temperatures, most of which are located in the South. ...
... We explore how the estimated coefficients in the main panel regression (4) evolve through time. This exploration is relevant because it could be the case that the negative economic effects of summer temperatures are diminished in the more recent part of the sample due to adaptation (e.g., due to widespread adoption of air conditioning technologies as documented by Barreca, Deschenes, and Guldi 2015). ...
Article
Full-text available
We document that seasonal temperatures have significant and systematic effects on the U.S. economy, both at the aggregate level and across a wide cross section of economic sectors. This effect is particularly strong for the summer: a F increase in the average summer temperature is associated with a reduction in the annual growth rate of state‐level output of 0.15 to 0.25 percentage points. We combine our estimates with projected increases in seasonal temperatures and find that rising temperatures could reduce U.S. economic growth by up to one‐third over the next century.
... The existing literature on the demographic impacts of climate change generally focused on biological impacts of heat on mortality and fertility (Deschenes, 2014;Barreca et al., 2015). By contrast, we focus on the potential for climate change to impact demographic outcomes via altering economic incentives. ...
... More generally, our work contributes to the very small but important literature examining the demographic impacts of climate change (Barreca et al., 2015;Casey et al., 2017). This literature is important for two key reasons. ...
... [1][2][3][4][5][6]. Fetuses and infants are especially sensitive to hot temperatures because their thermoregulatory and sympathetic nervous systems are not fully developed (7,8), with prior research showing that extreme heat during the prenatal period and shortly after birth has adverse effects on birth weight and infant mortality (9,10). ...
... In other words, for each individual, we calculate the hypothetical exposure to temperature in each critical period had he or she been born 2 y before his or her actual date of birth. We choose a 2-y lead to avoid confounding our estimates with any possible conception/fertility effects of temperature (10,33,35). Our leads should thus be uncorrelated with the actual treatment effect of exposure during gestation or in the first year of life. ...
Article
Significance Recent work has demonstrated how exposure to extreme temperatures influences contemporaneous health outcomes, such as infant mortality and morbidity. Additional research has explored how shocks to the early-life environment affect long-run human capital outcomes. However, there is little evidence on the possible long-term consequences of exposure to extreme temperatures in utero or in early childhood. This paper begins to fill this gap by studying long-run effects of temperature on measures of individuals’ economic wellbeing around age 30 y. We find that adult economic outcomes are negatively correlated with prenatal exposure to days with mean temperatures exceeding 32 °C. This relationship is completely mitigated among individuals born in counties with high rates of access to air conditioning.
... The demand for the source of energy depends on its usage of it. Research confirms that the temperature increase has an impact on the economy of a country (Barreca, Olivier and Melanie (2015) The Positive Side ...
Article
Full-text available
Heat wave has become an epic problem and is recurring every year and is lasting for many days. The days are becoming hotter than before and are fatal to individuals. An increased torture to the earth is the reason why the planet warms up extensively. The impact of heat waves directly impacts the economy when productivity decreases due to various reasons. Along with growth, carbon footprints have to be minimized for the climate to stabilize.
... DICE-EMR incorporates endogenous mortality but not an endogenous fertility; the fertility rate remains exogenously determined by the 2019 UN World Population Prospects. Although climate change is likely to affect the fertility rate 107 , the emerging literature on the topic suggests that climate will affect fertility through several different channels, some of which will tend to increase the fertility rate 107 and some of which will tend to decrease the fertility rate 108 . The overall effect of climate on the fertility rate is not yet clear from the literature, even directionally. ...
Article
Full-text available
Many studies project that climate change can cause a significant number of excess deaths. Yet, in integrated assessment models (IAMs) that determine the social cost of carbon (SCC) and prescribe optimal climate policy, human mortality impacts are limited and not updated to the latest scientific understanding. This study extends the DICE-2016 IAM to explicitly include temperature-related mortality impacts by estimating a climate-mortality damage function. We introduce a metric, the mortality cost of carbon (MCC), that estimates the number of deaths caused by the emissions of one additional metric ton of CO2. In the baseline emissions scenario, the 2020 MCC is 2.26 × 10 ‒4 [low to high estimate −1.71× 10 ‒4 to 6.78 × 10 ‒4 ] excess deaths per metric ton of 2020 emissions. This implies that adding 4,434 metric tons of carbon dioxide in 2020—equivalent to the lifetime emissions of 3.5 average Americans—causes one excess death globally in expectation between 2020-2100. Incorporating mortality costs increases the 2020 SCC from 37to37 to 258 [−69to69 to 545] per metric ton in the baseline emissions scenario. Optimal climate policy changes from gradual emissions reductions starting in 2050 to full decarbonization by 2050 when mortality is considered.
... A expectativa é de que um número menor de fi lhos permita que a mulher se dedique mais ao mercado de trabalho e, com um nível de educação mais elevado, passe a investir mais na formação do capital humano dos fi lhos (Almond;Currie, 2011). Soma-se a isso a possibilidade de a taxa de fecundidade ser sensível às mudanças climáticas, seja por conta de fatores biológicos (Fisch et al., 2003), ou por resposta comportamental aos eventos climáticos extremos (Barreca et al., 2015), sugerindo que a omissão dessa variável controle pode enviesar o impacto da fl utuação das chuvas sobre a TMC. ...
Article
Full-text available
The current study aims to investigate the impact of rainfall regime of the municipalities of the Ceará state on child health, proxied by the child mortality rate (CMR), in census years (1991, 2000 and 2010). The regressions show a negative relationship between CMR and rainfall fluctuations, in which the exposure to infectious diseases arises as the main mechanism effect. It is also observed that CMR is particularly responsive to the occurrence of episodes of severe/extreme droughts. This result is particularly worrisome, once the climate change predictions indicate an increase in the duration and intensification of droughts in the Northeast region of Brazil. Estimates based on such projections, suggest that the loss of human capital in childhood due to the future drops in municipal rainfall level can reach 1,5% of the state GDP until the end of the 21st century.
... We thank two anonymous referees for helpful comments that improved the paper. 9 A recent study finds that temperature may have long-run effects on fertility via reproductive health [6], a finding which is consistent with evidence on short-run temperature fluctuations and seasonality [7,8]. Similarly, climate change can cause other large societal disruptions, such as natural disasters and civil war, that may also impact fertility patterns [9][10][11][12]. ...
Article
Full-text available
We examine the potential for climate change to impact fertility via adaptations in human behavior. We start by discussing a wide range of economic channels through which climate change might impact fertility, including sectoral reallocation, the gender wage gap, longevity, and child mortality. Then, we build a quantitative model that combines standard economic-demographic theory with existing estimates of the economic consequences of climate change. In the model, increases in global temperature affect agricultural and non-agricultural sectors differently. Near the equator, where many poor countries are located, climate change has a larger negative effect on agriculture. The resulting scarcity in agricultural goods acts as a force towards higher agricultural prices and wages, leading to a labor reallocation into this sector. Since agriculture makes less use of skilled labor, climate damage decreases the return to acquiring skills, inducing parents to invest less resources in the education of each child and to increase fertility. These patterns are reversed at higher latitudes, suggesting that climate change may exacerbate inequities by reducing fertility and increasing education in richer northern countries, while increasing fertility and reducing education in poorer tropical countries. While the model only examines the role of one mechanism, it suggests that climate change could have an impact on fertility, indicating the need for future work on this important topic.
... If we only look at the hurricanes that happen in months that were unusually warm, there is a correlation of 0.814 between the destruction index value and the temperature variable. 15 In addition to the correlation with the destruction index, the results showing that heat causes fewer births is consistent with the findings of Barreca et al. (2015), where they find that heat waves cause a decline in the birth rate 9 months later. From Column (2) we can see that the inclusion of weather variables leads to a small reduction in the magnitude of our destruction index although the significance level is unchanged. ...
Thesis
Full-text available
Natural disasters have always been and probably always will be a problem for humans and their settlements. With global warming seemingly increasing the frequency and strength of the climate related disasters, and more and more people being settled in urban centers, the ability to model and predict damage is more important than ever.The aim of this thesis has been to model and analyze a broad range of disaster types and the kind of impact that they have. By modeling damage indices for disaster types as different as hurricanes and volcanic eruptions, the thesis helps with understanding both similarities and differences between how disasters work and what impact they have on societies experiencing them. The thesis comprises four different chapters in addition to this introduction, where all of them include modeling of one or more types of natural disasters and their impact on real world scenarios such as local budgets, birth rates and economic growth.Chapter 2 is titled “Natural Disaster Damage Indices Based on Remotely Sensed Data: An Application to Indonesia". The objective was to construct damage indices through remotely sensed and freely available data. In short, the methodology exploits that one can use nightlight data as a proxy for economic activity. Then the nightlights data is matched with remote sensing data typically used for natural hazard modeling. The data is then used to construct damage indices at the district level for Indonesia, for different disaster events such as floods, earthquakes, volcanic eruptions and the 2004 Christmas Tsunami. The chapter is forthcoming as a World Bank Policy Research Paper under Skoufias et al. (2017a).Chapter 3 utilizes the indices from Chapter 2 to showcase a potential area of use for them. The title is “The Reallocation of District-Level Spending and Natural Disasters: Evidence from Indonesia" and the focus is on Indonesian district-level budgets. The aim was to use the modeled intensity from Chapter 2 to a real world scenario that could affect policy makers. The results show that there is evidence that some disaster types cause districts to move costs away from more general line items to areas such as health and infrastructure, which are likely to experience added pressure due to disasters. Furthermore, volcanic eruptions and the tsunami led to less investment into more durable assets both for the year of the disaster and the following year. This chapter is also forthcoming as a World Bank Policy Research Paper under Skoufias et al. (2017b).The fourth chapter, titled “Urban Global Impact of Earthquakes from 2004 through 2013", is a short chapter focusing on earthquake damage and economic growth. This chapter is an expansion of the index used in the previous two chapters, where we use global data instead of focusing on a single country. Using a comprehensive remotely sensed dataset of contour mapsof global earthquakes from 2004 through 2013 and utilizing global nightlights as an economic proxy we model economic impact in the year of the quakes and the year after. Overall, it is shown that earthquakes negatively impact local urban light emissions by 0.7 percent.Chapter 5 is named “A Whirlwind Romance: The Effect of Hurricanes on Fertility in Early 20th Century Jamaica" and deviates from the prior chapters in that it is a historical chapter that looks at birth rates in the early 1900s. The goal was to use the complete and long-term birth database for Jamaica and match this with hurricane data to check fertility rates. We create a hurricane destruction index derived from a wind speed model that we combine with data on more than 1 million births across different parishes in Jamaica. Analyzing the birth rate following damaging hurricanes, we find that there is a strong and significant negative effect of hurricane destruction on the number of births.
... There is some evidence that fertility is lower in summer and that summer temperature extremes lead to lower fertility (34,35). There is also some suggestion that the seasonality of births in turn influences rates of childhood diseases and mortality (36,37). ...
Article
Research on environmental change has often focused on changes in population as a significant driver of unsustainability and environmental degradation. Demographic pessimism and limited engagement with demographic realities underpin many arguments concerning limits to growth, environmental refugees, and environment-related conflicts. Re-engagement between demographic and environmental sciences has led to greater understanding of the interactions between the size, composition, and distribution of populations and exposure to environmental risks and contributions to environmental burdens. We review the results of this renewed and far more nuanced research frontier, focusing in particular on the way demographic trends affect exposure, sensitivity, and adaptation to environmental change. New research has explained how migration systems interact with environmental challenges in individual decisions and in globally aggregate flows. Here we integrate analysis on demographic and environmental risks that often share a root cause in limited social freedoms and opportunities. We argue for a capabilities approach to promoting sustainable solutions for a more mobile world.
... In the past 50 years, the earth has experienced more extreme temperature events and larger temperature fluctuations (Peterson et al. 2013;Grotjahn et al. 2016;Jiang et al. 2016). Many studies have examined the impacts of temperature changes on agriculture, health, productivity, social conflict, and economic growth (Niemelä et al. 2002;Federspiel et al. 2004;Schlenker and Roberts 2009;Schlenker and Lobell 2010;Feng et al. 2010;Hsiang 2010;Fisher et al. 2012;Deschênes and Greenstone 2012;Heal and Park 2013;Dell et al. 2014;Heutel et al. 2017; Barreca et al. 2015;Burke et al. 2015;Graff Zivin et al. 2018). The question to what extent temperatures affect human capital formation and productivity is highly relevant for quantifying the economic impacts of weather changes. ...
Article
Full-text available
This paper studies the short-run impacts of temperature on human performance in the computer-mediated environment using server logs of a popular online game in China. Taking advantage of the quasi-experiment of winter central heating policy in China, we distinguish the impacts of outdoor and indoor temperature and find that low temperatures below 5 ∘C decrease game performance significantly. Non-experienced players suffered larger performance drop than experienced ones. Access to central heating attenuates negative impacts of low outdoor temperatures on gamers’ performance. High temperatures above 21 ∘C also lead to drops in game performance. We conclude that expanding the current central heating zone will bring an increase in human performance by approximately 4% in Shanghai and surrounding provinces in the winter. While often perceived as a leisure activity, online gaming requires intense engagement and the deployment of cognitive, social, and motor skills, which are also key skills for productive activities. Our results draw attention to potential damages of extreme temperature on human performance in the modern computer-mediated environment.
... Recent contributions to this literature have investigated the effects of immediate temperature on outcomes ranging from economic production (Dell et al., 2009;Burke et al., 2015) through the onset of conflict (Hsiang et al., 2013), to mortality rates (Barreca et al., 2016) and human reproductive behavior-with consequences for physical health and educational outcomes of the offspring (Wilde et al., 2017), and potentially for overall population growth (Barreca et al., 2015). Inspired by another growing body of literature-that on fetal origins, i.e., the impact of intrauterine conditions during gestation on later-life outcomes-I take a step back and consider behavioral implications of temperature shocks in utero. ...
Article
Full-text available
Climate change has not only led to a sustained rise in mean global temperature over the past decades, but also increased the frequency of extreme weather events. This paper explores the effect of temperature shocks in utero on later-life taste for cooperation. Using historical climate data combined with data on child and adult behavior in public goods games, I show that abnormally high ambient temperatures during gestation are associated with decreased individual contributions to the public good in a statistically and economically significant way. A 1 standard deviation rise in mean ambient temperature during gestation is associated with a 10% point decrease in children's cooperation rate in a dichotomous public goods game, and the reduced taste for cooperation lasts into adulthood.
... The existing literature on the demographic impacts of climate change has generally focused on biological impacts of heat on mortality and fertility 25,26 . By contrast, I focus on the potential for climate change to impact demographic outcomes via altering economic incentives for migration. ...
Article
Full-text available
Climate change impacts may drive affected populations to migrate. However, migration decisions in response to climate change could have broader effects on population dynamics in affected regions. Here, I model the effect of climate change on fertility rates, income inequality, and human capital accumulation in developing countries, focusing on the instrumental role of migration as a key adaptation mechanism. In particular, I investigate how climate-induced migration in developing countries will affect those who do not migrate. I find that holding all else constant, climate change raises the return on acquiring skills, because skilled individuals have greater migration opportunities than unskilled individuals. In response to this change in incentives, parents may choose to invest more in education and have fewer children. This may ultimately reduce local income inequality, partially offsetting some of the damages of climate change for low-income individuals who do not migrate.
... apresenta evidências de uma relação negativa entre a contagem média de espermatozoides e a temperatura global. Todavia, segundo os autores, não há um consenso na literatura sobre a consistência do mecanismo biológico. Uma das razões é o fato de que são os países industrializados os responsáveis pela tendência de queda na taxa de fertilidade global.Barreca et al. (2015) mostram que elevações na temperatura por causa das mudanças climáticas afetarão a taxa de fertilidade da população nos Estados Unidos, afetando a sazonalidade dos nascimentos. 5 Embora as áreas urbanas concentrem boa parte da infraestrutura de saúde e outros serviços públicos, o adensamento populacional facilita a propagação de doenças ...
... Recent work based in developed countries has shown that local weather events can determine the timing of conception, affecting fertility rates in the succeeding months. This can happen either because of biological reasons or parental preferences ( Barreca et al., 2015) or because of a forward-looking parental behavior regarding the optimal timing of birth ( Clarke et al., 2016). In sections A and B of the Online Appendix we perform a rigorous analysis to test for fertility changes in response to local weather events. ...
Article
The discussion on the effects of climate change on human activity has primarily focused on how increasing temperature levels can impair human health. However, less attention has been paid to the effect of increased climate variability on health. We investigate how in utero exposure to temperature variability, measured as the fluctuations relative to the historical local temperature mean, affects birth outcomes in the Andean region. Our results suggest that exposure to a temperate one standard deviation relative to the municipality’s long-term temperature mean during pregnancy reduces birth weight by 20 grams and increases the probability a child is born with low birth weight by a 0.7 percentage point. We also explore potential channels driving our results and find some evidence that increased temperature variability can lead to a decrease in health care and increased food insecurity during pregnancy.
... Hsiang & Jina (2015) compare predictions based on microlevel estimates with macrolevel cross sections for tropical cyclone impacts and conclude that results are largely consistent. In a remarkable higher-order test, Barreca et al. (2015) find that cross-sectional variation in the intra-annual variance in temperature, when applied to Equation 37, is a good predictor of cross-sectional patterns of intra-annual variance in birth rates. ...
Article
Full-text available
Identifying the effect of climate on societies is central to understanding historical economic development, designing modern policies that react to climatic events, and managing future global climate change. Here, I review, synthesize, and interpret recent advances in methods used to measure effects of climate on social and economic outcomes. Because weather variation plays a large role in recent progress, I formalize the relationship between climate and weather from an econometric perspective and discuss the use of these two factors as identifying variation, highlighting trade-offs between key assumptions in different research designs and deriving conditions when weather variation exactly identifies the effects of climate. I then describe recent advances, such as the parameterization of climate variables from a social perspective, use of nonlinear models with spatial and temporal displacement, characterization of uncertainty, measurement of adaptation, cross-study comparison, and use of empirical estimates to project the impact of future climate change. I conclude by discussing remaining methodological challenges. Expected final online publication date for the Annual Review of Resource Economics Volume 8 is October 05, 2016. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.
Article
This paper evaluates the short-term health effects of in utero drought shock using repeated cross-section household data on Malawi. The main finding reveals that the effects of in utero harvest variability caused by rainfall shocks on child growth indices are driven by the deleterious effects of negative rainfall deviations, namely droughts. Negative rainfall deviation during the agricultural season prior to the gestational period of a child leads to a 21.8 per cent average local level reduction in age-standardized height scores, with the counterpart positive rainfall deviation having no apparent effect. The paper also uses harvest and consumption patterns to establish an important link between early-life malnutrition and growth serving as a precursor for the fetal period programming hypothesis in the literature. The direct impact of embryonic period shocks on growth provides supportive evidence on potential interaction between nutritional and environmental pathways.
Article
Full-text available
We study the behavioral changes caused by marijuana use on sexual activity, contraception, and birth counts by applying a differences-in-differences approach that exploits the variation in timing of the introduction of medical marijuana laws (MMLs) among states. We find that MMLs cause an increase in sexual activity, a reduction in contraceptive use conditional on having sex, and an increase in number of births. There is also suggestive evidence on temporary increases in the state-year gonorrhea rate. These changes may be attributed to behavioral responses including increased attention to the immediate hedonic effects of sexual contact, increased sexual frequency, as well as delayed discounting and ignoring the future costs associated with sex. Our findings on births suggest that behavioral factors can counteract the physiological changes from marijuana use that tend to decrease fertility. Our findings are robust to a broad set of tests.
Preprint
Full-text available
For a free desk copy, go to the publisher's website: https://us.sagepub.com/en-us/nam/social-scientific-research/book257582. Social Scientific Research provides a comprehensive introduction to research methods in the social sciences, covering all key stages of the research process, from design to analysis, and helps readers navigate some of the biggest challenges in research. Features: • wide range of qualitative, quantitative and mixed methods • dedicated chapters on research questions, ethics, literature reviews, and writing· • numerous examples from academic research and real life experiences • array of activities, tips, exercises, and illustrations https://us.sagepub.com/en-us/nam/social-scientific-research/book257582 https://us.sagepub.com/en-us/nam/social-scientific-research/book257582 "fun, engaging, and intelligent book about the basics of research design." Gary King Weatherhead University Professor Harvard University “For faculty, teaching how to conduct social science research is known to be notoriously difficult. For students, learning research methods is mind-numbing. Brancati's book offers a solution to this decades-long dilemma. Inter-weaving concepts with examples from cutting-edge research, Social Scientific Research succinctly explains what makes good social science and how to do it." Kosuke Imai Professor, Director of Center for Statistics and Machine Learning Princeton University “the broadest and most accessible text I have seen.” Robert Y. Shapiro Wallace S. Sayre Professor of Government Columbia University Social Scientific Research is an important book…readable, comprehensive, and a great starting point for those new to research in the social sciences. Brancati—a masterful mentor to both undergraduate and graduate researchers—covers research design, both quantitative and qualitative methods, and provides rich practical guidance for those doing their own research projects or assessing the work of others. Andrew D. Martin Dean, College of Literature, Science, and the Arts University of Michigan
Article
Full-text available
Large-scale climate events can have enduring effects on population size and composition. Natural disasters affect population fertility through multiple mechanisms, including displacement, demand for children, and reproductive care access. Fertility effects, in turn, influence the size and composition of new birth cohorts, extending the reach of climate events across generations. We study these processes in New Orleans during the decade spanning Hurricane Katrina. We combine census data, ACS data, and vital statistics data to describe fertility in New Orleans and seven comparison cities. Following Katrina, displacement contributed to a 30% decline in birth cohort size. Black fertility fell, and remained 4% below expected values through 2010. By contrast, white fertility increased by 5%. The largest share of births now occurs to white women. These fertility differences—beyond migration-driven population change—generate additional pressure on the renewal of New Orleans as a city in which the black population is substantially smaller in the disaster’s wake.
Article
This paper examines the impact of exposure to early life rainfall shock on children's anthropometric growth status and other welfare outcomes. The study exploits World Bank repeated cross-section household data on Malawi and exogenous variation in precipitation measures across localities to identify the impact of drought and flood shocks on health, schooling and satisfaction levels. Our main estimate for children's anthropometric growth reveals that an incidence of drought shock leads to a resultant average decrease of 15%, 17% and 43% in age-standardized weight z-scores for shocks experienced at in-utero stage, first and second years respectively. Correspondingly, the relative impacts of an incidence of drought shock on age-standardized height z-scores are 14%, 15% and 27%. In contrast, the impacts of flood shock on each of these outcomes deteriorate over the outlined reference periods. On the adult dimension, we find that adults who face in-utero drought shock are more likely to have greater school entry delays and be unhappy with their current economic situations. However, this adulthood result pertains to male adults in our sample.
Research
Full-text available
Exposure to high temperatures during pregnancy is generally associated with low birth weight---a proxy for endowment. But whether such early life shock is further related to welfare losses in adulthood is still unknown. Utilizing random temperature fluctuations across 123 counties in China, we examine the relationships between high temperatures during pregnancy and birth weight and later outcomes. One standard deviation of high temperature days during pregnancy triggers about 0.17 kilograms loss of birth weight, and further in adulthood 1.63 cm decrease in height and 0.86 years less of schooling. Health and intelligence outcomes are adversely affected as well. The impacts are concentrated in the first and third trimesters. Such effects should become part of the calculations of the costs of global warming. Back-of-the-envelope predictions suggest that at the end of the 21st century newborns on average weigh 54.36-210.44 grams less. And the losses in height and education years are 0.52-2.02 centimeters and 0.26-1.01 years, respectively. We also argue these patterns are more likely consistent with physiological effects than with income effects, because total precipitation and high temperatures in the growing season of one year before birth have no significant effects.
Article
Full-text available
Because of the substantial energy demands of reproduction, the brain must temper the fertility of individuals to match nutritional availability. Under-nutrition is associated with infertility in humans and animals. The brain uses adipose- and gut-derived hormones, such as leptin, insulin and ghrelin, to modulate the activity of the GnRH neuronal network that drives reproduction. It is becoming clear that there are both direct and indirect pathways acting on GnRH neurones. A PubMed search was performed using keywords associated with neuropeptides and metabolic hormones that are associated with reproductive and energy balance axes. Evidence that neurones which produce galanin, galanin-like peptide, kisspeptin, alpha-melanocyte-stimulating hormone, neuropeptide Y and oxytocin convey metabolic information to the reproductive axis is presented. The extent to which these neurones express receptors for metabolic hormones is variable but interactions between them allows for complex intermingling of information. Available metabolic fuels modulate hormone input to these neurones, leading in turn to altered GnRH release and appropriate drive to the gonads. The consequent change in sex steroid production is likely to contribute to co-ordination of the network. We hypothesize that the absence of an estrogenic milieu during anovulation compared with presence of estradiol during follicular maturation is important for the regulation of most of the neuropeptides. An improved understanding of the normal responses to energy deprivation may also help to identify novel therapeutic targets for infertility that often accompanies metabolic disorders, such as diabetes, obesity and polycystic ovary syndrome.