Duncan Thomas

Duke University | DU · Department of Economics

The 2004 Indian Ocean tsunami was an extremely destructive event in Aceh, Indonesia, killing over 160,000 people and destroying infrastructure, homes, and livelihoods over miles of coastline. In its immediate aftermath, affected populations faced a daunting array of challenges. At the population level, questions of how the disaster affected childre...

Cardiovascular disease is among the most common causes of death around the world. As rising incomes in low and middle-income countries are accompanied by increased obesity, the burden of disease shifts towards non-communicable diseases, and lower-income settings make up a growing share of cardiovascular disease deaths. Comparative investigation of...

Despite significant research on the effects of stress on the hypothalamic–pituitary–adrenal (HPA) axis, questions remain regarding long-term impacts of large-scale stressors. Leveraging data on exposure to an unanticipated major natural disaster, the 2004 Indian Ocean tsunami, we provide causal evidence of its imprint on hair cortisol levels fourte...

Across the globe, human and animal populations and the ecosystems in which they reside are experiencing pressures from climate change, both from slow-onset gradual changes and from rapid-onset events that are often large-scale and more intense. These pressures affect the health and resources of those exposed to them, but at present our knowledge of...

The impact of exposure to a major unanticipated natural disaster on the evolution of survivors' attitudes toward risk is examined, exploiting plausibly exogenous variation in exposure to the 2004 Indian Ocean tsunami in combination with rich population-representative longitudinal survey data spanning the five years after the tsunami. Respondents ch...

Extreme events causing death and property destruction are on the rise across the globe. We document the long-term consequences for population health of exposure to an extreme event, the 2004 Indian Ocean earthquake and tsunami, which killed an estimated quarter of a million people worldwide. Using data from an extremely rich population-representati...

Exposure to disasters and other extreme events is rising across the globe, but the impact on long-term mortality risks of affected populations is not established. We examine how mortality and individual-specific traumatic exposures at the time of the disaster affect mortality risks of survivors over the subsequent ten years, using data from Aceh, I...

Background Stress is associated with elevated cardiometabolic health risks, but establishing a causal mechanism is challenging, and evidence of the longer-term effects of large-scale stressors on health is limited. To fill these gaps, we investigated the effect of elevated stress from direct exposure to the 2004 Indian Ocean tsunami on diabetes ris...

Glycated hemoglobin (HbA1c) measured using high-performance liquid chromatography (HPLC) assays with venous blood and dried blood spots (DBS) are compared for 143 paired samples collected in Aceh, Indonesia. Relative to gold-standard venous-blood values, DBS-based values reported by the HPLC are systematically upward biased for HbA1c<8% and the fra...

Exposure to extreme events has been hypothesized to affect subsequent mortality because of mortality selection and scarring effects of the event itself. We examine survival at and in the five years after the 2004 Indian Ocean earthquake and tsunami for a population-representative sample of residents of Aceh, Indonesia who were differentially expose...

Background The 2004 Indian Ocean earthquake, among the largest earthquakes in recorded history, spawned a major tsunami that devastated coastal communities in Aceh, Indonesia. This large-scale, natural disaster resulted in more than 170 000 deaths, displaced half a million people, and devastated large swathes of built infrastructure, arable land, a...

We investigate whether living arrangements respond to an arguably exogenous shift in the distribution of power in family economic decision-making. In the early 1990s, the South African Old Age Pension was expanded to cover most black South Africans above a sex-specific age cut-off resulting in a substantial increase in the income of older South Afr...

Understanding of human vulnerability to environmental change has advanced in recent years, but measuring vulnerability and interpreting mobility across many sites differentially affected by change remains a significant challenge. Drawing on longitudinal data collected on the same respondents who were living in coastal areas of Indonesia before the...

On 26 December 2004, a magnitude 9.2 earthquake off the west coast of the northern Sumatra, Indonesia, resulted in 160,000 Indonesians killed. We examine the Defense Meteorological Satellite Program-Operational Linescan System night-time light imagery brightness values for 307 communities in the Study of the Tsunami Aftermath and Recovery (STAR), a...

Identifying the impact of parental death on the well-being of children is complicated because parental death is likely to be correlated with other, unobserved factors that affect child well-being. Population-representative longitudinal data collected in Aceh, Indonesia, before and after the December 2004 Indian Ocean tsunami are used to identify th...

Indonesia established its Village Midwife Program in 1989 to combat high rates of maternal mortality. The program's goals were to address gaps in access to reproductive health care for rural women, increase access to and use of family planning services, and broaden the mix of available contraceptive methods. In this study, we use longitudinal data...

While deleterious consequences of smoking on health have been widely publicized, in many developing countries, smoking prevalence is high and increasing. Little is known about the dynamics underlying changes in smoking behavior. This paper examines socio-economic and demographic characteristics associated with smoking initiation and quitting in Mex...

The extent to which education provides protection in the face of a large-scale natural disaster is investigated. Using longitudinal population-representative survey data collected in two provinces on the island of Sumatra, Indonesia, before and after the 2004 Indian Ocean tsunami, we examine changes in a broad array of indicators of well-being of a...

No abstract available.

This study examines links between early life circumstances and adult socioeconomic status and obesity and hypertension in the adult Mexican population. We use data from the Mexican Family Life Survey (MxFLS) collected in 2002 for people aged 20 or older (N = 14,280). We found that men with low education and women with more education have significan...

Over 130,000 people died in the 2004 Indian Ocean tsunami. The correlates of survival are examined using data from the Study of the Tsunami Aftermath and Recovery (STAR), a population‐representative survey collected in Aceh and North Sumatra, Indonesia, before and after the tsunami. Children, older adults and females were the least likely to surviv...

Substantial international aid is spent reducing the cost of contraception in developing countries, as part of a larger effort to reduce global fertility and increase investment per child worldwide. The importance for fertility behaviors of keeping contraceptive prices low, however, remains unclear. Targeting of subsidies and insufficient price vari...

Attrition is the Achilles heel of longitudinal surveys. Drawing on our experience in the Indonesia Family Life Survey, we describe survey design and field strategies that contributed to minimizing attrition over four waves of the survey. The data are used to illustrate the selectivity of respondents who attrit from the survey and, also the selectiv...

The literature suggests that men and women may have different preferences. This paper exploits a social experiment in which women in treatment households were given a large public cash transfer (PROGRESA). In an effort to disentangle the effect of additional income in the household from the effect of changing the distribution of income within the h...

Socio-economic status (SES) and health go hand in hand: better off people tend to be in better health across the globe, within populations and over the life course. A critical review of both experimental and non- experimental evidence indicates that, in some contexts, health has a causal impact on SES. Fetal health and health in early life appear t...

We assessed the levels and correlates of posttraumatic stress reactivity (PTSR) of more than 20,000 adult tsunami survivors by analyzing survey data from coastal Aceh and North Sumatra, Indonesia. A population-representative sample of individuals interviewed before the tsunami was traced in 2005 to 2006. We constructed 2 scales measuring PTSR by us...

Between 1996 and 1998, Russia experienced a spectacular decline in economic activity which was followed by a dramatic rebound between 1998 and 2000. We use panel data to examine the impact of variation in household resources on six dimensions of nutritional status, distinguishing longer-run from short-term fluctuations in resources. Nutritional sta...

We used nationally representative longitudinal data from the Mexican Family Life Survey to determine whether recent migrants from Mexico to the United States are healthier than other Mexicans. Previous research has provided little scientific evidence that tests the "healthy migrant" hypothesis. Estimates were derived from logistic regressions of wh...

In recent years, significant advances have been made in better understanding the complex relationships between health and development. This reflects the combined effects of methodological innovations at both the theoretical and empirical level, the integration of insights from the biological and health sciences into economic analyses as well as imp...

The practice of individualized medicine for therapy or prevention could be informed by studies of genetic modifiers of treatment effects. This special case of gene–environment interaction studies offers several unique opportunities by exploiting random assignment of treatments. Two basic approaches are possible, one based on genetic studies added t...

The 1997 Indonesian financial crisis resulted in severe economic dislocation and political upheaval, and the detrimental consequences for economic welfare, physical health, and child education have been previously established in numerous studies. We also find the crisis adversely impacted population psychological well-being. We document substantial...

Since 2000, there have been a number of spaceborne satellites that have changed the way we assess and predict natural hazards. These satellites are able to quantify physical geographic phenomena associated with the movements of the earth's surface (earthquakes, mass movements), water (fl oods, tsunamis, storms), and fi re (wildfi res). Most of thes...

Although numerous epidemiologic studies now use models of intraurban exposure, there has been little systematic evaluation of the performance of different models. In this present article we proposed a modeling framework for assessing exposure model performance and the role of spatial autocorrelation in the estimation of health effects. We obtained...

National Institutes of Health (AR44422, N01-AR-7-2232, 5R01-HL049609-14, IR01-AG021917-01A1); Genome Canada and Associations AFP; Polyarctique-Groupe Taitbout; Rhumatisme et Travail; Arthritis Research Campaign; Unversity of Minnesota; Minnesota Supercomputing Institute; National Institute of General Medical Sciences (R01 GM31575)

Whether local exposure to major roadways adversely affects lung-function growth during the period of rapid lung development that takes place between 10 and 18 years of age is unknown. This study investigated the association between residential exposure to traffic and 8-year lung-function growth. In this prospective study, 3677 children (mean age 10...

Experimental data suggest that asthma exacerbation by ambient air pollutants is enhanced by exposure to endotoxin and allergens; however, there is little supporting epidemiologic evidence. We evaluated whether the association of exposure to air pollution with annual prevalence of chronic cough, phlegm production, or bronchitis was modified by dog a...

Previous contributions to the literature have used data on agricultural production activities in West Africa to show that plots of land managed by women are less productive (on average) than the ones farmed by their husbands. This would seem to indicate a rejection of the intrahousehold efficiency/cooperation hypothesis. The present study re-examin...

The authors propose a new statistical procedure that utilizes measurement error models to estimate missing exposure data in health effects assessment. The method detailed in this paper follows a Bayesian framework that allows estimation of various parameters of the model in the presence of missing covariates in an informative way. The authors apply...

Results from studies of traffic and childhood asthma have been inconsistent, but there has been little systematic evaluation of susceptible subgroups. In this study, we examined the relationship of local traffic-related exposure and asthma and wheeze in southern California school children (5-7 years of age). Lifetime history of doctor-diagnosed ast...

Twenty years ago, the National Institute of Child Health and Human Development (NICHD) issued a request for proposals that resulted in the National Survey of Families and Households (NSFH), a unique survey valuable to a wide range of family scholars. This paper describes the efforts of an interdisciplinary group of family demographers to build on t...

Several investigators have discussed various reasons for the large and consistent difference in the relative risk estimates per unit exposure to air pollution derived from time-series and cohort study designs. This article considers whether the two study designs are estimating fundamentally different parameters even though both are commonly express...

In the 1990s, the Indonesian government placed over 50,000 midwives in communities throughout the country. We examine how this expansion in health services affected children's height-for-age. To address the problem that midwives were not randomly allocated to communities, the estimation exploits the biology of childhood growth, the timing of the in...

We combined data from a population-based longitudinal survey with satellite measures of aerosol levels to assess the impact of smoke from forest fires that blanketed the Indonesian islands of Kalimantan and Sumatra in late 1997 on adult health. To account for unobserved differences between haze and nonhaze areas, we compared changes in the health o...

Associations have been found between long-term exposure to ambient air pollution and cardiovascular morbidity and mortality. The contribution of air pollution to atherosclerosis that underlies many cardiovascular diseases has not been investigated. Animal data suggest that ambient particulate matter (PM) may contribute to atherogenesis. We used dat...

Households are rather complicated structures in developing countries, where it is not uncommon to find many adults living under the same roof and sharing the cooking pot. Most of the empirical investigation of models that highlight individualistic behavior within the household has been confined, however, to the characterization of decision-making b...

Genetic Analysis Workshop 14 (GAW14) was held September 7–10, 2005, in Noordwijkerhout, The Netherlands. The overarching theme was the comparison of microsatellite and single-nucleotide polymorphism (SNP) markers for genome-wide scans, and the statistical methods that can best exploit the information provided in such scans for linkage and associati...

We consider two-stage case-control designs for testing associations between single nucleotide polymorphisms (SNPs) and disease, in which a subsample of subjects is used to select a panel of "tagging" SNPs that will be considered in the main study. We propose a pseudolikelihood [Pepe and Flemming, 1991: JASA 86:108-113] that combines the information...

Whether exposure to air pollution adversely affects the growth of lung function during the period of rapid lung development that occurs between the ages of 10 and 18 years is unknown. In this prospective study, we recruited 1759 children (average age, 10 years) from schools in 12 southern California communities and measured lung function annually f...

Recently, there has been much interest in the use of Bayesian statistical methods for performing genetic analyses. Many of the computational difficulties previously associated with Bayesian analysis, such as multidimensional integration, can now be easily overcome using modern high-speed computers and Markov chain Monte Carlo (MCMC) methods. Much o...

The immediate effects of the Asian crisis on the well-being of Indonesians are examined using the Indonesia Family Life Survey, an ongoing longitudinal household survey. There is tremendous diversity in the effect of the shock: for some households, it was devastating; for others it brought new opportunities. A wide array of mechanisms was adopted i...

This paper uses data from the Russian Longitudinal Monitoring Survey (RLMS) to examine the relationship between nutritional status and both longer-run household resources and short-run fluctuations in household resources. We evaluate six measures of nutrition – gross energy intake, two dimensions of diet quality, body mass index (BMI), which is a m...

The year 1998 saw the onset of a major economic and financial crisis in Indonesia. GDP fell by 12% that year. The effect on education of the next generation is examined. On average, household spending on education declined, most dramatically among the poorest households. Spending reductions were particularly marked in poor households with more youn...

We estimate the causal effect of mandatory participation in the military service on the involvement in criminal activities. We exploit the random assignment of young men to military service in Argentina through a draft lottery to identify this causal effect. Using a unique set of administrative data that includes draft eligibility, participation in...

We present a method to perform fine mapping by placing haplotypes into clusters on the basis of risk. Each cluster has a haplotype "center." Cluster allocation is defined according to haplotype centers, with each haplotype assigned to the cluster with the "closest" center. The closeness of two haplotypes is determined by a similarity metric that me...

Abstract We present a method for using slopes and intercepts from a linear regression of a quantitative trait as outcomes in segregation and linkage analyses. We apply the method to the analysis of longitudinal systolic blood pressure (SBP) data from the Framingham Heart Study. A first-stage linear model was fit to each subject's SBP measurements...

Abstract The Genetic Analysis Workshop 13 simulated data aimed to mimic the major features of the real Framingham Heart Study data that formed Problem 1, but under a known inheritance model and with 100 replicates, so as to allow evaluation of the statistical properties of various methods. The pedigrees used were the 330 real pedigree structures (...

The relationship of bronchitic symptoms to ambient particulate matter and to particulate elemental and organic carbon (OC), nitrogen dioxide (NO2), and other gaseous pollutants was examined in a cohort of children with asthma in 12 Southern California communities. Symptoms, assessed yearly by questionnaire from 1996 to 1999, were associated with th...

We propose a method to analyze haplotype effects using ideas derived from Bayesian spatial statistics. We assume that two haplotypes that are similar to one another in structure are likely to have similar risks, and define a distance metric to specify the appropriate level of closeness between the two haplotypes. Through the choice of distance metr...

Matched retrospective life history data collected from the same individuals in two waves of the Malaysian Family Life Survey provide a unique opportunity to evaluate the quality of long-term recall data in a rapidly changing developing country. Recall quality, measured by consistency of incidence and dating of moves reported 12 years apart, is high...

Missing data are a great concern in longitudinal studies, because few subjects will have complete data and missingness could be an indicator of an adverse outcome. Analyses that exclude potentially informative observations due to missing data can be inefficient or biased. To assess the extent of these problems in the context of genetic analyses, we...

Herrnstein and Murray report that conditional on maternal “intelligence” (AFQT scores), child test scores are little affected by variations in socioeconomic status. Using the same data, we demonstrate that their finding is very fragile. We explore the effect of adopting a more representative sample of children, including blacks and Latinos, allowin...

The recent completion of the first draft of the human genome sequence and advances in technologies for genomic analysis are generating tremendous opportunities for epidemiologic studies to evaluate the role of genetic variants in human disease. Many methodological issues apply to the investigation of variation in the frequency of allelic variants o...

A cohort of 1,678 Southern California children, enrolled as fourth graders in 1996, was followed for 4 years to determine whether the growth in lung function of the children was associated with their exposure to ambient air pollutants. These subjects comprised the second cohort of fourth grade children participating in the Children's Health Study....

A positive correlation between health and economic prosperity has been widely documented, but the extent to which this reflects a causal effect of health on economic outcomes is very controversial. Two classes of evidence are examined. First, carefully designed random assignment studies in the laboratory and field provide compelling evidence that n...

After over a quarter century of sustained economic growth, Indonesia was struck by a large and unanticipated crisis at the end of the 20th Century. Real GDP declined by about 12% in 1998. Using 13 years of annual labor force data in conjunction with two waves of a household panel, the Indonesia Family Life Survey (IFLS), this paper examines the imp...

Recent research suggests that household decision-making may be influenced by the relative power of husbands and wives. But, empirical measurement of relative power has been extremely difficult. Using data that were specially collected to address this issue, the value of resources that husbands and wives brought to the marriage are treated as an ind...

There is a longstanding interest in how decisions about resource allocations are made within households and how those decisions affect the welfare of household members. Much empirical work has approached the problem from the perspective that if preferences differ, welfare outcomes will depend on the power of individuals within the household to exer...

Indonesian women's power relative to that of their husbands is examined to determine how it affects use of prenatal and delivery care. Holding household resources constant, a woman's control over economic resources affects the couple's decision-making. Compared with a woman with no assets that she perceives as being her own, a woman with some share...

Data from three waves of the Indonesia Family Life Survey (IFLS) are used to examine follow-up and attrition in the context of a large scale panel survey conducted in a low-income setting. Household-level attrition between the baseline and first follow-up four years later is less than 6 percent; the cumulative attrition between the baseline and sec...

Health status is hard to measure. It is widely recognized that health is multi-dimensional reflecting the combination of an array of factors that include physical, mental and social well-being, genotype and phenotype influences as well as expectations and information. A multitude of health indicators have been used in scientific studies drawing on...

Indonesian women's power relative to that of their husbands is examined to determine how it affects use of prenatal and delivery care. Holding household resources constant, a woman's control over economic resources affects the couple's decisionmaking. Compared with a woman with no assets that she perceives as being her own, a woman with some share...

We use data from the Indonesia Family Life Survey to investigate the impact of a major expansion in access to midwifery services on health and pregnancy outcomes for women of reproductive age. Between 1990 and 1998 Indonesia trained some 50,000 midwives. Between 1993 and 1997 these midwives tended to be placed in relatively poor communities that we...

This paper focuses on dynamics within couples, although the authors recognize that dynamics among extended family members and across generations are of substantial interest. Decisions about resource allocations, control over economic resources, whether and how much one works, are all examined.

This study uses data from the British National Child Development Survey (NCDS) to examine interactions between socio-economic status (SES), children's test scores, and future wages and employment. We find that children of lower SES have both lower age 16 test scores and higher returns to these test scores in terms of age 33 wages and employment pro...

this paper provides new empirical evidence on how households smooth out the effects of unanticipated shocks.

Research on Head Start suggests that effects on test scores "fade out" more quickly for black children than for white children. We use data from the 1988 wave of the National Educational Longitudinal Survey to show that Head Start black children go on to attend schools of worse quality than other black children. We do not see any similar pattern am...

The question of how access to services affects health outcomes is critical for policy makers allocating resources across different programs, but it is difficult to answer with cross-sectional data sets. The authors use data from a panel survey in Indonesia (the Indonesia Family Life Survey) that spans a period of a major expansion in access to midw...

Data from three waves of the Indonesian Family Life Survey (IFLS) are used to examine attrition in the context of a large scale panel survey conducted in a low income setting.

Little is known about the long-term effects of participation in Head Start. This paper draws on unique non-experimental data from the Panel Study of Income Dynamics to provide new evidence on the effects of participation in Head Start on schooling attainment, earnings, and criminal behavior. Among whites, participation in Head Start is associated w...

This paper shows that increases in the minimum wage rate can have ambiguous effects on the working hours and welfare of employed workers in competitive labor markets. The reason is that employers may not comply with the minimum wage legislation and instead pay a lower subminimum wage rate. If workers are risk neutral, we prove that working hours an...