Duncan C. Thomas

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Virtually all models of the household have the minimal implication that the equilibrium allocation of resources is Pareto efficient. Within many African households, agricultural production is simultaneously carried out on many plots controlled by different members of the household. Pareto efficiency implies that variable factors should be allocated(More)
Despite the yield of recent genome-wide association (GWA) studies, the identified variants explain only a small proportion of the heritability of most complex diseases. This unexplained heritability could be partly due to gene--environment (G×E) interactions or more complex pathways involving multiple genes and exposures. This Review provides a tutorial on(More)
This study examines the impact of 4 health measures on wages of urban workers in Brazil. Data are obtained from the 1974-75 Estudo Nacional da Despesa Familiar among a sample population over 14 years old for wages earned by respondents 15-50 years old. The 4 health measures include height, body mass index (weight divided by height squared), per capita(More)
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 data on 798(More)
If household income is pooled and then allocated to maximize welfare then income under the control of mothers and fathers should have the same impact on demand. With survey data on family health and nutrition in Brazil, the equality of parental income effects is rejected. Unearned income in the hands of a mother has a bigger effect on her family's health(More)
To study possible chronic respiratory effects of air pollutants, we initiated a 10-yr prospective cohort study of Southern California children, with a study design focused on four pollutants: ozone, particulate matter, acids, and nitrogen dioxide (NO2). Twelve demographically similar communities were selected on the basis of historic monitoring information(More)
The impact of participation in Head Start is investigated using a national sample of children. Comparisons are drawn between siblings to control for selection. Head Start is associated with large and significant gains in test scores among both whites and African-Americans. However, among African-Americans, these gains are quickly lost. Head Start(More)
BACKGROUND 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. METHODS In this prospective study, we recruited 1759 children (average age, 10 years) from schools in 12 southern California communities and measured lung(More)
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 asthma and(More)
OBJECTIVES 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. METHODS Estimates were derived from logistic(More)