Todd E. Elder

Selection on Observed and Unobserved Variables: Assessing the Effectiveness of Catholic Schools.

In this paper we measure the effect of Catholic high school attendance on educational attainment and test scores. Because we do not have a good instrumental variable for Catholic school attendance, we develop new estimation methods based on the idea that the amount of selection on the observed explanatory variables in a model provides a guide to the amount of selection on the unobservables. We also propose an informal way to assess selectivity bias based on measuring the ratio of selection on unobservables to selection on observables that would be required if one is to attribute the entire effect of Catholic school attendance to selection bias. We use our methods to estimate the effect of attending a Catholic high school on a variety of outcomes. Our main conclusion is that Catholic high schools substantially increase the probability of graduating from high school and, more tentatively, attending college. We find little evidence of an effect on test scores.

An Evaluation of Instrumental Variable Strategies for Estimating the Effects of Catholic Schooling

Several previous studies have relied on religious affiliation and the proximity to Catholic schools as exogenous sources of variation for identifying the effect of Catholic schooling on a wide variety of outcomes. Using three separate approaches, we examine the validity of these instrumental variables. We find that none of the candidate instruments is a useful source of identification in currently available data sets. We also investigate the role of exclusion restrictions versus nonlinearity as the source of identification in bivariate probit models. The analysis may be useful as a template for the assessment of instrumental variables strategies in other applications.

Kindergarten Entrance Age and Children's Achievement: Impacts of State Policies, Family Background, and Peers

We present evidence that the positive relationship between kindergarten entrance age and school achievement primarily reflects skill accumulation prior to kindergarten, rather than a heightened ability to learn in school among older children. The association between achievement test scores and entrance age appears during the first months of kindergarten, declines sharply in subsequent years, and is especially pronounced among children from upper-income families, a group likely to have accumulated the most skills prior to school entry. Finally, having older classmates boosts a childs test scores but increases the probability of grade repetition and diagnoses of learning disabilities such as ADHD.

Subjective Survival Probabilities in the Health and Retirement Study: Systematic Biases and Predictive Validity

Recent research has demonstrated that retirement planning and well-being are closely tied to probabilistic forecasts about future events. Using longitudinal data from the Health and Retirement Study, I show that individuals’ subjective survival forecasts exhibit systematic biases relative to life table data. In particular, many respondents fail to account for increases in yearly mortality rates with age, both longitudinally and in crosssection. Additionally, successive cohorts of the near elderly do not appear to revise survival forecasts to match increases in longevity. Forecasting bias may merely be due to the framing of questions designed to elicit expectations, but real biases may result in suboptimal savings rates and timing of retirement. Cross-sectional variation in subjective survival forecasts also appears to reflect differences in cognitive ability across respondents, suggesting that subjective information is more relevant for some individuals than others. Despite these shortcomings, subjective mortality probabilities predict actual mortality and portfolio choice, and they contain information not found in selfreported health status or objective measures of health limitations.

Donorcycles: Motorcycle Helmet Laws and the Supply of Organ Donors

Traffic safety mandates are typically designed to reduce the harmful externalities of risky behaviors. We consider whether motorcycle helmet laws also reduce a beneficial externality by decreasing the supply of viable organ donors. Our central estimates show that organ donations resulting from fatal motor vehicle accidents increase by 10 percent when states repeal helmet laws. Two features of this association suggest that it is causal: first, nearly all of it is concentrated among men, who account for over 90 percent of all motorcyclist deaths, and second, helmet laws are unrelated to the supply of donors who die in circumstances other than motor vehicle accidents. The estimates imply that every death of a helmetless motorcyclist prevents or delays as many as .33 death among individuals on organ transplant waiting lists.

A Deadly Disparity: A Unified Assessment of the Black-White Infant Mortality Gap

Abstract We provide a unified assessment of a striking disparity in the United States: the differential rate at which white and black infants die. We separate the overall mortality gap into three temporal components—fitness at birth, conditional neonatal mortality, and conditional post-neonatal mortality—and quantify the extent to which each of the components can be predicted using a flexible reweighting method. Almost 90 percent of the overall mortality gap is due to differential fitness at birth, little of which can be predicted by racial differences in background characteristics. The remaining mortality gap stems from conditional post-neonatal mortality differences, nearly all of which can be predicted by background characteristics. The predictability of the mortality gap has declined substantially over the past two decades, largely because the mortality gap among extremely low-fitness infants is increasingly unrelated to background characteristics.

The Incredible Shrinking Program: Trends in SSI Participation of the Aged

Supplemental Security Income (SSI) program features have changed little since 1974, and elderly participation has declined over time. A behavioral model of aged household SSI participation is used to simulate various policy alternatives. The failure to index asset limits has had little effect on participation, but the indexation of both asset and income disregard limits would have raised the SSI participation rate of aged households by about 30%. If, in addition, states had been required to hold the real value of their supplemental benefits constant over time, the elderly household SSI participation rate would have doubled. Finally, the model is used to estimate the impact of a recent policy change, the increase in the normal retirement age (NRA) in the regular Social Security system. When fully phased in, the increase in the NRA is predicted to raise the SSI participation of elderly households from 4.9% to 7.8%.

The Changing Character of the Black–White Infant Mortality Gap, 1983–2004

OBJECTIVES We examined how changes in demographic, geographic, and childbearing risk factors were related to changes in the Black-White infant mortality rate (IMR) gap over 2 decades. METHODS Using 1983-2004 Vital Statistics, we applied inverse probability weighting methods to examine the relationship between risk factors and 3 outcomes: the overall IMR gap, its birth weight component, and its conditional (on birth weight) IMR component. RESULTS The unexplained IMR gap (the part not related to observed risk factors) was stable, changing from 5.0 to 5.3 deaths per 1000 live births. By contrast, the explained gap declined from 4.6 to 1.9. The decline in the explained gap was driven by the changing relationship between risk factors and IMR. Further analysis revealed that most of the unexplained gap occurred among infants weighing less than 1000 grams at birth, whereas most of the explained gap occurred among infants weighing more than 1000 grams. CONCLUSIONS The unexplained gap was stable over the last 2 decades, but the explained gap declined markedly. If the stability of the unexplained gap continues, even complete convergence of risk factors would reduce the Black-White IMR gap by only one quarter.

Public Health Insurance and SSI Program Participation Among the Aged

Previous researchers have noted that the ‘categorical’ Medicaid eligibility accompanying the welfare programs Aid to Families with Dependent Children (AFDC) and Supplemental Security Income (SSI) often far exceeds the value of these programs’ cash benefits. It may be the case that the accompanying health insurance, not the cash benefit, is often the decisive factor in welfare participation. If so, welfare participation should decrease when cash and health insurance benefits are unbundled. We present a simple model of program participation with heterogeneous valuation of health insurance and transaction costs of participation. We evaluate the following four implications of the model: 1) SSI participation declines with the expansion of alternative routes to Medicaid (i.e., noncategorical Medicaid); 2) the availability of noncategorical Medicaid increases Medicaid participation among SSI nonparticipating eligibles; 3) the average SSI benefit collected by welfare recipients is higher when noncategorical Medicaid is available; and 4) the average SSI benefit rejected by nonparticipating SSI eligibles is higher when noncategorical Medicaid is available. Overall, the findings on the model’s testable implications are mixed. The estimates imply strikingly large effects of the presence of alternative routes to Medicaid on both SSI and Medicaid participation, but the results for the hypotheses about SSI benefit amounts are sensitive to controls for recipient characteristics.

Explained and unexplained racial and regional inequality in obesity prevalence in the United States

ABSTRACT Objective: There are substantial racial and regional disparities in obesity prevalence in the United States. This study partitioned the mean Body Mass Index (BMI) and obesity prevalence rate gaps between non-Hispanic blacks and non-Hispanic whites into the portion attributable to observable obesity risk factors and the remaining portion attributable to unobservable factors at the national and the state levels in the United States (U.S.) in 2010. Design: This study used a simulated micro-population dataset combining common information from the Behavioral Risk Factor Surveillance System and the U.S. Census data to obtain a reliable, large sample representing the adult populations at the national and state levels. It then applied a reweighting decomposition method to decompose the black-white mean BMI and obesity prevalence disparities at the national and state levels into the portion attributable to the differences in distribution of observable obesity risk factors and the remaining portion unexplainable with risk factors. Results: We found that the observable differences in distribution of known obesity risk factors explain 18.5% of the mean BMI difference and 20.6% of obesity prevalence disparities between non-Hispanic blacks and non-Hispanic whites. There were substantial variations in how much the differences in distribution of known obesity risk factors can explain black-white gaps in mean BMI (−67.7% to 833.6%) and obesity prevalence (−278.5% to 340.3%) at the state level. Conclusion: The results from this study demonstrate that known obesity risk factors explain a small proportion of the racial, ethnic and between-state disparities in obesity prevalence in the United States. Future etiologic studies are required to further understand the causal factors underlying obesity and racial, ethnic and geographic disparities.