Current Research
Below is a descriptive list of current research centers and projects funded through CHW. The centers are listed first, and projects appear in alphabetical order by title.
More information about research conducted by CHW affiliates, including publications resulting from these projects, is available on their individual websites.
Center for Research on Experience and Wellbeing
The Center for Health and Wellbeing is home to a National Institute of Aging Roybal Center, called the Center for Research on Experience and Wellbeing (CREW). The overall objectives of CREW are to (1) develop new methods for the measurement of wellbeing and health and (2) use these measures to better understand and document the experience of aging. The measures developed will be used to analyze how different life circumstances and situations contribute to the overall quality of life across the life cycle. The combination of measurements of the affective experience of situations and activities with measurements of the time spent by the population in these activities, currently collected by the Department of Labor Statistics, will contribute to the development of an experimental system of National Wellbeing Accounts. CHW affiliates involved in the Center include Angus Deaton, Alan Krueger and Daniel Kahneman. External researchers include Arthur Stone (Stony Brook University), former CHW visiting fellow David Schkade (University of California, San Diego) and Norbert Schwarz (University of Michigan).
Demography of Aging Center
The Center for Health and Wellbeing is home to a Demography of Aging Center, funded by the National Institute of Aging. The Demography of Aging Center, started in 2004, fosters new research on the interrelationships between socioeconomic status and health as people age; examines the determinants of decision-making and wellbeing among the elderly; and explores the determinants and policy consequences of increased longevity and population aging across and within countries over time. An area of special emphasis is research on how HIV/AIDS is affecting the health and living conditions of the elderly. The key CHW faculty associates working on this project are Anne Case, Jonathan Cohen, Angus Deaton, Noreen Goldman, and Daniel Kahneman. The center is directed by Anne Case.
The center has funded 26 pilot projects to date. The active pilot projects are:
- Social Status and Health over the Life Course: Evidence from the Whitehall II Study – PIs: Anne Case and Christina Paxson
This project examines the extent to which early life health and environment among British civil servants, followed over time in the Whitehall II panel study (WII), can explain their health and socioeconomic status in late-middle age and old age. We are looking at how early life experiences—as measured by adult height, as well as retrospective information on childhood socioeconomic status and health—influence economic outcomes (income, asset holdings, employment grade) and health (chronic conditions, difficulties with activities of daily living, self-assessed health, and mental health) among Whitehall participants. Using several British cohort studies, our earlier research found that taller individuals attain higher levels of education, sort into higher grade occupations, and have higher levels of full-time employment and earnings. We found that the associations between height and labor market outcomes are largely due to the correlation of height and cognitive ability. Using the wealth of information on cognitive function, health outcomes, and labor market outcomes in the Whitehall data, we are analyzing how height and early-life health is related to trajectories of labor market outcomes, and quantifying the extent to which the relationship between height and labor market outcomes is due to education, cognitive function and adult health.
- Family Reunification and Older Immigrants: Implications for Health and Social Service Utilization – PI: Marta Tienda
This project examines the service utilization patterns of elderly immigrants by entry pathway and length of U.S. residence; region of origin; employment history/status; living arrangements; and personal attributes. The goals are: to become familiar with the data strengths and limitations for studying income and service utilization of foreign born elders; to develop a descriptive profile of recent and established older immigrants by year of arrival, pathway to senior status, and region of origin; and, to characterize the labor force and program participation of older immigrants by sponsorship as a senior vs. aging in situ statuses.
- Scarcity, Cognitive Function, and Stress – PI: Eldar Shafir
This project investigates central aspects of the psychology of scarcity, a novel theoretical framework that looks at some of the psychological challenges faced by people living in poverty, and the behavioral patterns that ensue. Perhaps the defining property of being poor is that money is scarce; there is not enough of it to meet the demands imposed by daily life. One important corollary of monetary scarcity is the persistent need to think about tradeoffs: to compute the budgetary consequences of even small financial decisions (“If I purchase X, what will I not be able to purchase instead?”). This, we posit, yields a demanding and ever-present set of cognitive challenges that are encountered considerably less frequently in the lives of those who are financially more comfortable. The chronic challenges of tradeoff thinking, we suggest, may help explain the greater planning and decision difficulties, including health and financial troubles, so frequently exhibited by the poor, particularly as they age.
- The Efficacy of Smartphone Technology for Collecting Data on Disadvantaged Men with Chronic Health Problems – PI: Sara McLanahan
This project examines the efficacy of collecting information on health status and behaviors using smartphones as compared to traditional phone-based interviewing. Our sample will consist of men who have recently been released from prison and who are searching for a job. While the average age of this population is mid- to late-30s, these men have often experienced premature aging due to the accumulation of high-risk lifestyles, stressful neighborhood conditions, lack of basic healthcare, and socioeconomic disadvantage. The men in our sample are likely to have high rates of physical health, mental health, and substance use problems, and are similar to older people in the general population in terms of morbidity and mortality rates.
- Behavioral and fMRI Studies of Economic Preference – PI: Jonathan Cohen
Given the growing use of intertemporal choice questionnaires, it is becoming increasingly important to understand (1) the factors that influence people’s responses, (2) how these differ from real world behavior, and (3) how these instruments can be modified to make them better indicators of impulsivity and intertemporal decision-making in real world circumstances. This project addresses these questions. There are several confounding factors in the standard questionnaires that may explain their apparent failure to match real world intertemporal decision-making. In collaboration with David Laibson at Harvard University, we are conducting a series of behavioral and neuroimaging pilot studies that test several hypotheses concerning the source of the anomalously high discount rates elicited by intertemporal choice questionnaires.
Health Grand Challenge
The Health Grand Challenge, established in 2007 as part of the University’s Grand Challenges Program and administered by CHW, is an integrated research and teaching program that seeks solutions to the pressing problems posed by infectious disease around the globe.
The Health Grand Challenge has funded 12 projects to date. The active projects are:
- Enhanced Production of Influenza Vaccine by Inhibition of Multiple Viral Restriction Factors - PI: Thomas Shenk
A set of human proteins have been identified that act to block the growth of viruses. They are termed viral restriction factors. We discovered several of the known viral restriction factors, including the family of sirtuin proteins. It is possible to delete or “knock down” expression of viral restriction factors to improve the growth of viruses. We plan to identify an optimal set of viral restriction factors that, when inactivated (deleted or knocked down), markedly improve the growth of influenza virus in cultured cells. Improved yields of the virus has the potential to revolutionize the influenza vaccine industry, markedly reducing the cost of goods and making the vaccine available to a much larger portion of the world’s population.
- Graphene Nanosensors for Ubiquitous Diagnostics - PI: Michael McAlpine
Direct interfacing of nanosensors onto biomaterials could revolutionize health quality monitoring and adaptive threat detection. Graphene is capable of highly sensitive analyte detection. Here we show that the nanoscale nature of graphene allows it to be printed onto water-soluble silk. This in turn permits intimate biotransfer of graphene nanosensors onto biomaterials, including teeth, skin and food. The result is a fully interfaced sensing platform which can be tuned to detect target analytes. For example, via self-assembly of peptides onto graphene, we show bioselective detection of bacteria at single cell levels. Incorporation of a resonant coil eliminates the need for onboard power and external connections. Combining these elements yields two-tiered interfacing of peptide-graphene nanosensors with biomaterials. In particular, we demonstrate integration onto a tooth for remote monitoring of respiration and bacteria detection in saliva. This hierarchical interfacing of biomolecules with nanosensors and biomaterials represents a versatile approach for detecting biochemical targets.
- Health as an Ecosystem Service Around Tanzanian Lakes and National Parks – PI: Andrew Dobson
Although sub-Saharan Africa’s national parks provide significant foreign currency to the government, the revenues they generate are rarely invested in the surrounding community health systems. Rural natives living in the parks’ vicinity have minimal access to basic health care, and many by default rely on traditional healers for treatment for zoonotic and vector-borne diseases.
This project investigates the dynamics and control of zoonotic and vector-borne disease in East Africa and the ‘ecosystem service’ that biodiversity plays in buffering and reducing disease outbreaks. How much do local people benefit from the presence of national parks? Specifically, do the parks serve as sources of ‘trickle down’ revenue from tourism to the local community, or as sources of ‘trickle down’ infections that impact their health and that of their livestock? Alternatively, does the park present a significant opportunity cost through loss of land for forage and crops? Or does it in turn protect local people and domestic livestock from disease outbreaks through the presence of host species that are preferred by vectors, or by other biological mechanisms that buffer disease outbreaks and improve water quality and volume? The research will address the health and economic costs and benefits of conserving biodiversity in the national parks and wildlife reserves.
- Informational Structure of Infectious Diseases – PIs: Ramanan Laxminarayan and Simon Levin
Infectious diseases are carried by individuals, but survive in populations. The transmission of infectious disease is influenced possibly as much by information and human behavior as by the biology of the infection and the ecological landscape. In some sense, information and human behavior are part of the larger ecological landscape in which diseases operate but are relatively less understood than other features such as the population age structure, spatial detail or vector ecology (in the case of vector-borne diseases).
Research in economics and epidemiology has demonstrated that individual behavior is not static and changes with the risk of infection and effectiveness and cost of prevention and treatment. For example, the availability of inexpensive, effective treatment for malaria could reduce bednet purchase and use if individuals perceive a lower cost to being infected. These individual perceptions of risk are formed using a number of factors, including public information (such as on disease risk and prevalence), private information (on one’s own circumstances and behavior) and actions undertaken by others. The effect of herd immunity has been incorporated into disease models; but herd behavior and information cascades, which form the basis for how individuals acquire information, are also important. Taken together, the structure of public (both government and rest of society) and private information plays a key role in disease ecology and the dynamics of transmission.
Informational structure, just like spatial structure, could fundamentally change our understanding of disease progression, predictions of disease models, and effectiveness of public health interventions. Information is among the most powerful tools available to government authorities in time of disease outbreaks, and it is unclear how this tool ought to be used either by itself or in conjunction with other policies such as quarantining or mass vaccination. Also information from public authorities may have to preempt rumors and other sources of information that could exacerbate a disease outbreak.
- Political Islam and the politics of health care in the Arab world - PIs: Amaney Jamal, Tarek Masoud and Elizabeth Nugent
This research grant will contribute to a large, multi-country study of political Islam and its impact on health outcomes in the Arab world. The project seeks to define and quantify the Islamic share of the market for medical services, to identify where and to what social groups such services are offered, to test systematically how the provision of Islamic medical services translates (or fails to translate) into political support for parties espousing identifiably Islamic agendas. This project will also trace the impact of Islamist governance on health outcomes—particularly for women. Do they for example, strive to make basic health services more accessible to women and children? Do they limit funding for family planning or for infectious diseases linked to sexual activity?
The project will involve multiple methodologies: GIS mapping of Islamic clinics; interviews with Islamic healthcare providers; statistical analyses of the correlations between Islamic vote shares and the “Islamic” share of the medical market; experimental and mass surveys of citizens’ political attitudes, voting behavior, and patterns of health care usage; and close analyses of health care legislation introduced by Islamist parliamentarians. The grant will be used to undertake a study in Tunisia in the summer of 2013, with a view toward making a larger proposal to a major research agency, such as the National Science Foundation and National Institutes of Health, to undertake further, cross-national research. The project promises not only to shed light on how Islamists view health care, but also the relationship between the provision of health care and winning elections, and how political Islam affects human development outcomes in the countries in which it has risen to power.
- Predictive Models of Meningitis Risk in the African Meningitis Belt – PIs: Nicole E. Basta, Paul Ginoux and Elena Shevliakova
The complex ecological factors driving the distinct seasonality of meningococcal disease epidemics in the African meningitis belt are poorly understood. Evidence suggests that dust, low absolute humidity, rainfall, wind direction and velocity, land cover, and surface temperature may contribute, and a plausible biological mechanism by which these factors could increase risk of meningococcal disease among asymptomatic carriers has been proposed. We aim to develop, test, and validate an epidemiologic meningococcal disease risk model for Mali and Niger using climatic factors drawn from several high-resolution climate models including a recently published model of global dust circulation.
Our goal is to develop tools to better understand the role of environmental factors in predicting
meningitis outbreaks in Africa. Developing these tools will set the stage for more extensive research aimed at modeling epidemiologic risk across the entire meningitis belt and identifying high-priority areas that would most benefit from vaccination, thus addressing a significant public health challenge.
- The Role of Humoral Immunity in Human Health: How Does Infection Susceptibility Relate to Autoimmune Susceptibility? – PI: Andrea Graham
Antibodies are essential for resistance against infectious diseases such as malaria and influenza. Yet antibodies can also cause debilitating autoimmunity when they attack host tissue and/or accrue at such high densities that they damage organs. Despite the importance of these contrasting roles of antibody-mediated (humoral) immunity to human health, the overall relationship between risk of autoimmunity and resistance to infection remains unknown. Recent work on wild animals suggests that hosts actually experience a trade-off between autoimmune and infection susceptibilities. Might such a trade-off apply in people? The U.S. military has accrued a repository of serum samples that, combined with medical records of the serum donors, presents an opportunity to quantify the combined impacts of humoral immunity on human health. Using this resource will enable the pairing of an epidemiological analysis of infectious disease incidence in autoimmune individuals with a laboratory analysis of the strength of their antibody responses to infectious agents. In sum, the research project will use this longitudinal serum bank and database to test the idea that autoimmune susceptibility is associated with enhanced resistance to infectious disease.
- Wild baboons as a model to understand immune function and disease risk during pregnancy and lactation - PIs: Jeanne Altmann and Elizabeth Archie
Scientific understanding of women’s disease risk and immune function during pregnancy and lactation is surprisingly limited. This is partly because pregnant and lactating women are challenging study subjects; hence human studies are often constrained to small sample sizes, sub-optimal controls, and/or biased metadata. Our project will address these challenges by working in the well-studied Amboseli baboon population, which offers decades of dense, longitudinal sampling on behavior and physiology. We propose two aims to reveal how female reproductive status influences three major indices of immune function and disease risk: wound healing, the incidence of illness, and parasite burdens. Our preliminary results suggest that wound healing is delayed during lactation. The resulting data sets will be among the largest in the world on this topic, for either humans or animals, and the proposed project will place us in a competitive position to receive future funding on perinatal health.
Program on U.S. Health Policy
The Program on U.S. Health Policy, launched by CHW in early 2012, sponsors research and activities addressing aspects of domestic health care and health policy. The Program supports innovative faculty and student research, conferences, policy forums and special issues in health policy journals.
>> Call for faculty research proposals
The Program is currently supporting the following research projects:
- Exploring Small Area Variations in Children’s Health Care – PI: Janet Currie
One of the “stylized facts” about American medicine is that some areas spend much more on health care without achieving noticeably better results in terms of reductions in morbidity and mortality. Reining in such “excess” spending is an important goal of health care reform, yet we have little understanding of the reasons these variations exist. We do not even know how common they are in the non-elderly population, since virtually all of this research has been conducted using data on the elderly. It is possible that these patterns are quite different in the elderly and non-elderly since the elderly all have relatively generous health insurance coverage under the Medicare program. This research will first investigate small area variations in health care for children, and in subsequent health outcomes. The research will then investigate reasons that have been suggested for these variations including financial incentives facing providers; differences in patient populations; differences in legal regimes; spillovers from one provider to another in terms of practice style; and learning by individual practitioners.
- Improving maternity care in New Jersey: How do hospitals respond to policy mandates to reduce cesarean section rates and improve breastfeeding rates? – PI: Elizabeth Armstrong
This research proposes to investigate how the 50-some maternity hospitals in New Jersey are responding to maternity care policy mandates to reduce cesarean rates and increasing breastfeeding rates. Cesarean rates and breastfeeding rates are complex, multifactorial outcomes that reflect provider practices, institutional protocols, patient preferences, sociodemographic characteristics of the patient population, and cultural norms. The research project will analyze hospital-level and state-wide data, and conduct interviews with a range of actors from a sample of New Jersey hospitals, to investigate the following questions: How do providers and hospital administrators seek to achieve mandates to reduce cesareans and increase breastfeeding? What do they see as the most important determinants of these outcomes? How do they prioritize institutional responses? And what is the effect of these policy shifts on actual clinical practice as well as patient outcomes?
- Making Health Insurance Work: Data-Driven Incentive Alignment – PIs: Mark Braverman and Sylvain Chassang
Capitation schemes, in which plans are paid expected health care costs for the people who join them, are a key component of health care insurance policies, but existing schemes are subject to gaming by health plans seeking to attract patients with lower than expected cost of care. In the past ill designed capitation schemes have contributed to the failure of health insurance exchanges in Texas (1999) and California (2006). This research program, at the intersection of Economics and Computer Science, studies the value of large exhaustive data sets of patient characteristics in resolving this issue. It proposes novel uses for such data that go beyond standard data mining applications, and instead focuses on correct incentive provision.
- Social Identity, Disease Risk Perception, and Policy Prioritization: Experimental Research on Race and HIV/AIDS in the United States – PIs: Evan Lieberman and Yarrow Dunham
We propose to conduct a series of web-‐based survey experiments to investigate the implications of social identity theory for citizen risk perception and policy prioritization of a stigmatized condition. Perhaps unsurprisingly, we hypothesize that race is likely to be an important heuristic for citizen risk assessment in the face of uncertainty. Yet, we also propose that when primed to consider a disease as a stigmatized condition, members of stigmatized groups (such as Blacks in the U.S.) are more likely to downplay, or even deny, those risks in order to avoid the associated stigma or group shame. If our experimental results are consistent with our hypotheses, this may suggest that specific current practices of targeting African Americans as being most at risk for HIV and AIDS may yield unconsidered drawbacks. We also discuss additional hypotheses with respect to white Americans.
Differential Impacts of Environmental Policy on Infants in Poor and Minority Neighborhoods
Janet Currie, PI
Where people live impacts the hazards they are exposed to. Minority and low income children may be disproportionately exposed to environmental pollution, and may be less able to deal with the consequences of these exposures. Exposure during the fetal period and in infancy may be particularly harmful, leading to lifelong consequences. Hence, policies to clean up pollution might be expected to have particular benefits for poor and minority infants.
This research considers several such policies including Superfund cleanups, changes in regulations covering the Toxic Release Inventory, and the introduction of the electronic toll collection systems on roadways. These initiatives represent differing approaches to the amelioration of environmental problems. The study will ask whether vulnerable children suffer greater exposure, and whether vulnerable children are likely to benefit differentially from a given policy.
When measuring benefits, it is important to take account of potential effects through the housing market. When environmental policy is successful, it may increase housing costs and poor and minority children may be displaced. In this case, housing market effects could undo some of the positive effects of environmental cleanups for these children.
This research will involve the statistical analyses of a unique longitudinal data base created from millions of U.S. birth records. This data base has large samples of African American, Asian and Hispanic children. Less educated mothers, teen mothers, and mothers in high-poverty neighborhoods can also be identified.
The results of this study will shed new light on the environmental justice literature by examining the extent to which environmental policies close gaps in exposures and outcomes between poor and minority infants and others, as well as on the extent to which these policies displace vulnerable mothers and infants from the newly improved neighborhoods. These research outcomes in turn will show how spacial disparities in exposures arise, and how persistent they are likely to be. The ultimate goal of the research is to suggest policies to improve outcomes and minimize displacement. Since most neighborhood improvements can be expected to impact housing prices, the results will be relevant to other place-based policies.
Dimensions of Subjective Well-Being: Aging, Religiosity, and Adaptation
Angus Deaton, PI
The project, funded in August 2011 by the National Institute on Aging, is directed by Angus Deaton, in collaboration with Arthur Stone, Distinguished Professor of Psychiatry and Psychology at Stony Brook University, and Nobel Laureate Daniel Kahneman, Professor Emeritus of Psychology and Public Policy at Princeton. The project will study the use of self-reports as measures of well-being, with a view to advancing the measurement of subjective well-being and to advancing the understanding of whether and how such measures can and should be used in policy. The analysis rests on the distinction between different concepts of “happiness.” One concept relates to hedonic well-being, the continuous flow of feelings that is experienced on a moment to moment basis. The other is an overall view of how life is going, which comes from a considered judgment. Accumulating evidence suggests that these two concepts capture different aspects of human well-being, and that they respond differently to different circumstances.
The project will explore this distinction using large new data sets for the United States and for more than 150 countries around the world. It will look at how the different measures of self-reported well-being are related to life circumstances, with a particular focus on age. There are several hypotheses in economics and psychology about how subjective well-being should change over the life-cycle, and these will organize the investigations.
Another major line of investigation is the role of religiosity in well-being; the research will seek to better understand both the determinants of religiosity—why people become more religious as they age, why women are more religious than men—as well as the benefits or costs of religion and whether they are or are not universal around the world. The final topic is the extent to which subjective well-being is relative: for example, whether well-being depends on a person’s own income, or instead on income relative to the income of others. One hypothesis is that the well-known phenomenon of adaptation can often be mistaken for relativity, and that this has important consequences for thinking about economic policy for the elderly, including such issues as the taxation of social security benefits or incentives for postponing retirement.
An overarching theme of the work is to understand whether self-reports of well-being can be defended as guides to policy, or whether the criticisms of them by some philosophers and economists are sufficient to rule them out. A better understanding of adaptation is also a key for this last endeavor.
Fragile Families and Child Wellbeing Study
Sara McLanahan, PI
The Fragile Families and Child Wellbeing Study is following a cohort of nearly 5,000 children born in large U.S. cities between 1998 and 2000 (roughly three-quarters of whom were born to unmarried parents). The Study consists of interviews with both mothers and fathers at birth and again when children are ages one, three, five, and nine, plus in-home assessments of children and their home environments at ages three, five, and nine. The Study provides new information on the capabilities and relationships of parents, particularly unwed parents, as well as the effects of parental resources and public policies on children's wellbeing. The Study is a joint effort of the Center for Research on Child Wellbeing, CHW, Columbia University's Columbia Population Research Center, and the National Center for Children and Families. The Principal Investigators are Sara McLanahan and Christina Paxson at Princeton University and Irwin Garfinkel and Jeanne Brooks-Gunn at Columbia University. It is funded through grants from the Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD), and a consortium of private foundations and other government agencies.
Future of Children
Sara McLanahan, Editor in Chief
The Future of Children is a journal that seeks to promote effective policies and programs for children by providing policymakers, service providers, and the media with timely, objective information based on the best available research. The journal is a collaborative effort between the Woodrow Wilson School and The Brookings Institution. The journal draws on the expertise of three Woodrow Wilson School research centers, including the Center for Health and Wellbeing. Sara McLanahan, director of the Bendheim-Thoman Center for Research on Child Wellbeing, is editor-in-chief; senior editors include Janet Currie, Director of the Center for Health and Wellbeing, and Cecilia Rouse, director of the Education Research Section (ERS). Isabel Sawhill, vice president and director of the Economic Studies Program at the Brookings Institution, and Brookings senior fellow Ron Haskins fill out the journal's permanent editorial staff. Kris McDonald, Program Manager of the Center for Research on Child Wellbeing (CRCW), is the associate editor of The Future of Children. The journal is published twice a year. Each issue serves as a basis for a graduate course offered at the Woodrow Wilson School. The Future of Children website is www.futureofchildren.org.
Novel Longitudinal Observational Health Indicators in a Highly Social Wild Primate Model
Jeanne Altmann, PI
Jeanne Altmann and group of 10 biologists have been working together successfully since 2007 to accomplish two goals. The first goal is to build a database capturing the life histories of ~3900 individuals in seven species of non-human primates living under natural conditions over periods exceeding 25 years. This is an extraordinary dataset, representing a taxonomically diverse sample of species and a large timespan, which is essential for long-lived organisms like primates. The database serves both to store these valuable data and as a template for others developing similar datasets (Strier et al 2010, Methods in Ecology and Evolution). The second goal is to use the data to explore questions related to the demography of aging and to evolutionary ecology. Their first two analyses are now published in major journals. Bronikowski et al (2011 Science) compared aging metrics of the seven non-human primates to humans, finding that the pattern of senescence – reflected in mortality at the onset of adulthood and the rate of aging during adulthood – placed humans within the range of variation of their non-human relatives. This finding contradicts widely held views that humans exhibit unique extended aging patterns. Morris et al (2011, The American Naturalist) examined how three aspects of demographic variability – demographic variation, covariation and serial correlation -- affect fitness in a stochastic environment. This study highlighted the unusually low demographic variability in non-human primates relative to other animals, related perhaps to the primates’ cognitive complexity, social lives and generalist diets.
Using Vital Statistics Natality Data to Assess the Impact of Environmental Policy: The Examples of Superfund, the Toxic Release Inventory, and E-ZPass
Janet Currie, PI
This study investigates the extent to which geocoded Vital Statistics Natality data collected from birth certificates can be used to assess the impact of environmental policy changes. These records cover millions of births (in fact all births) over long periods of time. They include information about maternal background and birth outcomes as well as information about the precise residential location of mothers. Moreover, birth records can be linked to infant death records to yield large samples of infant deaths. Given residential addresses, it is possible to link mothers to information about nearby environmental hazards. It is also possible to link births to the same mother, so that the effect of changes in potential exposure can be assessed. The hypothesis being investigated is that these large and comprehensive data sets can shed useful light on the effects of environmental policy. The specific policies to be investigated include cleanups of hazardous waste (Superfund) sites, changes in information about toxic releases as tracked in the Toxic Release Inventory, and the implementation of E-ZPass at toll plazas on busy roadways in New Jersey and Pennsylvania.
