The Effects of Welfare and Taxes

这项研究包括两个项目和几个扩展。第一篇研究了最近的福利和税收变化对单身母亲的劳动力供给和计划参与的影响。广泛的项目：联邦和州的劳动所得税抵免（EITCs）， AFDC，食品券，医疗补助，儿童保育和AFOC培训项目进行了分析。还分析了1984年至1996年期间，以及至少两个大型微观数据集。在过去的十年里，这些项目发生了巨大的、往往是前所未有的变化。作为受这些政策影响的主要群体，单身母亲的就业也发生了前所未有的变化，这在很大程度上似乎是由于这些政策的变化。目前的工作主要集中在政策对就业的影响，工作时间较少。此外，重点是工作时间，计划变化对计划参与的影响，以及其他结果。这第一个项目在范围和时间上涵盖了许多以前的文献。许多被审查的重大政策变化以前没有被研究过，它们提供了一个机会来评估广泛的激励效应。第二个大型项目分析了福利倾向人群的迁移。各州在福利项目的慷慨程度上存在很大差异。移徙的可能性对国家政策产生重要影响，并影响到移徙者的福祉。移民的程度对于评估许多福利项目研究中的偏差很重要，这些研究使用跨州项目差异来确定政策效果。这一领域的研究产生了强烈矛盾的结果。即使在没有相互矛盾的结果的情况下，过去的许多研究在方法上也存在重大缺陷，这使他们的结果受到质疑。其中一些方法上的问题以前已经认识到，而另一些则没有。福利引起的移徙的程度是使用几个大型微观数据集和替代方法来检查的。这两个项目都有重要的方法论组成部分。两种方法都是基于对照组的。（有时称为准实验方法或自然实验）和结构方法的使用。这项工作将阐明结构和基于比较组的方法的识别假设和优缺点。在某些情况下，有可能通过估计一个结构模型来整合这两种方法的最佳方面，该模型具有识别变化的透明和合理的外生来源。该研究还将探讨一些原因的矛盾的结果，以前的工作。

This research involves two projects and several extensions.. The first examines the effects of recent welfare and tax changes on the labor supply and program participation of single mothers. A wide range of programs: federal and state Earned Income Tax Credits (EITCs), AFDC, Food Stamps, Medicaid, Child Care, and AFOC training programs is analyzed. Also analyzed is the period, 1984 1996, and at least two large micro data sets. In the past ten years there have been large, often unprecedented changes in these programs. There have also been unprecedented changes in the employment of single mothers, the primary group affected by these policies, that seem to be in large part due to these policy changes. The current work focuses mostly on policy effects on employment and to a lesser extent hours worked. In addition, focus is directed on hours worked, the effects of the program changes on program participation, and other outcomes. This first project encompasses in scope and time period much of the previous literature. Many of the large policy changes that are examined have not been previously studied and they offer an opportunity to evaluate a wide range of incentive effects. The second large project analyzes the migration of welfare prone populations. There are very large differences across states in the generosity of welfare programs. The possibility of migration has an important influence on state policies and affects the well being of recipients. The extent of migration is important in assessing the biases in much research on welfare programs that uses cross state program differences to identify policy effects. This area of research has produced strongly conflicting results. Even in the absence of the conflicting results, much of the past research has important methodological flaws which call their results into question. Some of these methodological problems have been previously recognized, while others have not The extent of welfare induced migration is examined using several large micro data sets and alternative approaches. Both of these projects have important methodological components. Both comparison group based methods.(sometimes called quasi experimental methods or natural experiments) and structural approaches are used. The work will elucidate the identifying assumptions and advantages and disadvantages of both structural and comparison group-based methods. In some cases, it is possible to integrate the best aspects of both approaches by estimating a structural model with transparent and plausibly exogenous sources of identifying variation. The research also will probe some of the reasons for the conflicting results of previous work.