Cognitive and Noncognitive Peer Effects in Early Education

We examine peer effects in early education by estimating value-added models with school fixed effects that control extensively for individual, family, peer, and teacher characteristics to account for the endogeneity of peer group formation. We find statistically significant and robust spillover effects from preschool on math and reading outcomes, but statistically insignificant effects on various behavioral and social outcomes. We also find that peer externalizing problems, which most likely capture classroom disturbance, hinder cognitive outcomes. Our estimates imply that ignoring spillover effects significantly understates the social returns to preschool

Temperature and the Allocation of Time: Implications for Climate Change

In this paper we estimate the impacts of climate change on the allocation of time using econometric models that exploit plausibly exogenous variation in daily temperature over time within counties. We find large reductions in U.S. labor supply in industries with high exposure to climate and similarly large decreases in time allocated to outdoor leisure. We also find suggestive evidence of short-run adaptation through temporal substitutions and acclimatization. Given the industrial composition of the US, the net impacts on total employment are likely to be small, but significant changes in leisure time as well as large scale redistributions of income may be consequential. In developing countries, where the industrial base is more typically concentrated in climate-exposed industries and baseline temperatures are already warmer, employment impacts may be considerably larger.

Air Pollution and Infant Health: Lessons from New Jersey

We examine the impact of three "criteria" air pollutants on infant health in New Jersey in the 1990s by combining information about mother's residential location from birth certificates with information from air quality monitors. In addition to large sample size, our work offers three important innovations: First, because we know the exact addresses of mothers, we select those mothers closest to air monitors to ensure a more accurate measure of air quality. Second, since we follow mothers over time, we control for unobserved characteristics of mothers using maternal fixed effects. Third, we examine interactions of air pollution with smoking and other predictors of poor infant health outcomes. We find consistently negative effects of exposure to pollution, especially carbon monoxide, both during and after birth. The effects are considerably larger for smokers than for nonsmokers as well as for older mothers. Since automobiles are the main source of carbon monoxide emissions, our results have important implications for regulation of automobile emissions.

The Impact of Pollution on Worker Productivity

Environmental protection is typically cast as a tax on the labor market and the economy in general. Since a large body of evidence links pollution with poor health, and health is an important part of human capital, efforts to reduce pollution could plausibly be viewed as an investment in human capital and thus a tool for promoting economic growth. While a handful of studies have documented the impacts of pollution on labor supply, this paper is the first to rigorously assess the less visible but likely more pervasive impacts on worker productivity. In particular, we exploit a novel panel dataset of daily farm worker output as recorded under piece rate contracts merged with data on environmental conditions to relate the plausibly exogenous daily variations in ozone with worker productivity. We find robust evidence that ozone levels well below federal air quality standards have a significant impact on productivity: a 10 ppb decrease in ozone concentrations increases worker productivity by 4.2 percent.

Air pollution and infant health: lessons from New Jersey

We examine the impact of three "criteria" air pollutants on infant health in New Jersey in the 1990s by combining information about mother's residential location from birth certificates with information from air quality monitors. Our work offers three important innovations: First, we use the exact addresses of mothers to select those closest to air monitors to improve the accuracy of air quality exposure. Second, we include maternal fixed effects to control for unobserved characteristics of mothers. Third, we examine interactions of air pollution with smoking and other risk factors for poor infant health outcomes. We find consistently negative effects of exposure to carbon monoxide, both during and after birth, with effects considerably larger for smokers and older mothers. Since automobiles are the main source of carbon monoxide emissions, our results have important implications for regulation of automobile emissions

The Effect of an Early Education Program on Adult Health: The Carolina Abecedarian Project Randomized Controlled Trial

Objectives. We explored whether a successful randomized controlled trial of early education, the Carolina Abecedarian Project (ABC), which enrolled infants from 1972 to 1977 at the Frank Porter Graham Child Development Institute in Chapel Hill, North Carolina, improved health outcomes and behaviors by 21 years of age. Methods. ABC randomized 111 infants to receive an intensive early education program or nutritional supplements and parental counseling alone; participants have been followed to the present day. We examined the effect of ABC on health outcomes and behavioral risk factors when participants were aged 21 years, and then explored the mediators of this relationship. Results. Relative to the control group, the ABC treatment group was previously found to have improved cognition and educational attainment. We found that the intervention also improved heath (P = .05) and health behaviors (P = .03) when participants were aged 21 years. These improvements in behaviors were not mediated by IQ, math and reading scores at 15 years of age, educational attainment, or health insurance. Conclusions. Effective early education programs may improve health and reduce risky health behaviors in adulthood

Unconventional Gas and Oil Drilling Is Associated with Increased Hospital Utilization Rates

Over the past ten years, unconventional gas and oil drilling (UGOD) has markedly expanded in the United States. Despite substantial increases in well drilling, the health consequences of UGOD toxicant exposure remain unclear. This study examines an association between wells and healthcare use by zip code from 2007 to 2011 in Pennsylvania. Inpatient discharge databases from the Pennsylvania Healthcare Cost Containment Council were correlated with active wells by zip code in three counties in Pennsylvania. For overall inpatient prevalence rates and 25 specific medical categories, the association of inpatient prevalence rates with number of wells per zip code and, separately, with wells per km2 (separated into quantiles and defined as well density) were estimated using fixed-effects Poisson models. To account for multiple comparisons, a Bonferroni correction with associations of p<0.00096 was considered statistically significant. Cardiology inpatient prevalence rates were significantly associated with number of wells per zip code (p<0.00096) and wells per km2 (p<0.00096) while neurology inpatient prevalence rates were significantly associated with wells per km2 (p<0.00096). Furthermore, evidence also supported an association between well density and inpatient prevalence rates for the medical categories of dermatology, neurology, oncology, and urology. These data suggest that UGOD wells, which dramatically increased in the past decade, were associated with increased inpatient prevalence rates within specific medical categories in Pennsylvania. Further studies are necessary to address healthcare costs of UGOD and determine whether specific toxicants or combinations are associated with organ-specific responses

Air quality and error quantity: pollution and performance in a high-skilled, quality-focused occupation

We provide the first evidence that short-term exposure to air pollution affects the work performance of a group of highly-skilled, quality-focused employees. We repeatedly observe the decision-making of individual professional baseball umpires, quasi-randomly assigned to varying air quality across time and space. Unique characteristics of this setting combined with high-frequency data disentangle effects of multiple pollutants and identify previously under-explored acute effects. We find a 1 ppm increase in 3-hour CO causes an 11.5% increase in the propensity of umpires to make incorrect calls and a 10 mg/m3 increase in 12-hour PM2.5 causes a 2.6% increase. We control carefully for a variety of potential confounders and results are supported by robustness and falsification checks