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Recent Scientific Accomplishments Gelbach’s research interests are in applied microeconomics, applied econometrics, and economics of the legal system. He has published papers in the American Economic Review on the effects of child care costs on maternal labor supply and on heterogeneous treatment effects (the latter being coauthored with Marianne P. Bitler of UC Irvine and Hilary W. Hoynes of UC Davis). Another paper, about the effects of welfare migration on optimal welfare benefit levels, was published in the Journal of Political Economy. Gelbach has published a number of other papers on welfare reform in the Journal of Human Resources and Demography (these papers included coauthors Bitler, Hoynes, and Madeline Zavodny of Agnes Scott College). An additional paper (coauthored with Bitler and Hoynes) on Canada’s Self-Sufficiency Project welfare reform program will be revised for a requested resubmission to the Journal of Public Economics. Two papers showing how to improve the accuracy of statistical inference in the presence of dependence within a small number of clusters and when there is dependence within multiple overlapping (non-nested) clusters have been submitted to the Review of Economics and Statistics and the Journal of Human Resources, respectively (these papers are coauthored with A. Colin Cameron and Douglas L. Miller, both of UC Davis). Gelbach does not currently have any externally-funded research. He has a pending R03 submitted to NICHD (see below under Future Research Plans). Gelbach is actively engaged in a number of projects. Together with coauthors Bitler and Hoynes, he is examining the implications of heterogeneous treatment effects on cost-benefit analysis for welfare programs when policymakers are inequality-averse. In another paper on welfare reform, Gelbach plans to use recently developed binary regression quantile estimation to evaluate whether welfare reform programs have had heterogeneous effects on fertility or marriage. A third paper on welfare reform (to be coauthored with Chris Herbst, a graduate student at the School of Public Policy at Maryland) will use data from state welfare reform experiments to investigate the share of the reduction in welfare participation by experiment subjects that can be attributed to program assignment, rather than economic growth or some other cause. He is currently working on a paper (with Shawn Bushway of SUNY-Albany) about bail-setting by judges seeking to minimize the social costs related to releasing defendants before trial, on the one hand, and jailing them, on the other. This paper is intimately related to the burgeoning literature on racial profiling in the stopped-motorist context. Gelbach and Bushway show that “hit-rate” tests generally do not provide a valid basis for testing for the existence of illegal (as opposed to rational statistical) racial discrimination; they show how to formulate a generalized test, provided that one has access to valid instrumental variables. Gelbach is also working on a paper (with Jonathan Klick of Florida State and Thomas Stratmann of George Mason) on obesity and the relative prices of healthy versus unhealthy foods. As data on food prices are available at the Census-region level, a key element of this paper will involve using a specialized bootstrap to overcome inferential difficulties that arise when the number of clusters is small---this technique is the one developed in the first paper with Cameron and Miller. Another paper involves the literature on the effects of income taxation on taxable income. Gelbach will point out problems with both the theoretical underpinnings of this literature and the empirical assessment of tax responsiveness. | ||||||||
Maryland Population Research Center
0124N Cole Student Activities Building (#162)
College Park, MD 20742
Phone: 301-405-6403
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