We develop a new method of estimating the impacts of tax policies that uses areas with little knowledge about the policy's marginal incentives as counterfactuals for behavior in the absence of the policy. We apply this method to characterize the impacts of the Earned Income Tax Credit (EITC) on...

Are teachers' impacts on students' test scores ("value-added") a good measure of their quality? This question has sparked debate largely because of disagreement about (1) whether value-added (VA) provides unbiased estimates of teachers' impacts on student achievement and (2) whether high-VA...

We analyze linear models with a single endogenous regressor in the presence of many instrumental variables. We weaken a key assumption typically made in this literature by allowing all the instruments to have direct effects on the outcome. We consider restrictions on these direct effects that...

We argue that the development and expansion of direct, secure access to administrative micro-data should be a top priority for the NSF. Administrative data offer much larger sample sizes and have far fewer problems with attrition, non-response, and measurement error than traditional survey data...

The debate between structural and reduced-form approaches has generated substantial controversy in applied economics. This article reviews a recent literature in public economics that combines the advantages of reduced-form strategies - transparent and credible identification - with an important...

It is well known that unemployment benefits raise unemployment durations. This result has traditionally been interpreted as a substitution effect caused by a distortion in the price of leisure relative to consumption, leading to moral hazard. This paper questions this interpretation by showing...

We survey the literature on social insurance, focusing on recent work that has connected theory to evidence to make quantitative statements about welfare and optimal policy. Our review contains two parts. We first discuss motives for government intervention in private insurance markets, focusing...

There is widespread concern that economics does not attract as broad or diverse a pool of talent as it could. For example, less than one-third of undergraduates who receive degrees in economics are women, significantly lower than in math or statistics. This article presents a case study of a new...

In this paper--the first in a series of two papers that use data on 21 billion friendships from Facebook to study social capital--we measure and analyze three types of social capital by ZIP code in the United States: (i) connectedness between different types of people, such as those with low vs....

Low levels of social interaction across class lines have generated widespread concern and are associated with worse outcomes, such as lower rates of upward income mobility. Here, we analyze the determinants of cross-class interaction using data from Facebook, building upon the analysis in the...