This paper empirically assesses the wage effects of the Job Corps program, one of the largest federally-funded job training programs in the United States. Even with the aid of a randomized experiment, the impact of a training program on wages is difficult to study because of sample selection, a...

This paper discusses inference for rational expectations models estimated via minimum distance methods by characterizing the probability beliefs regarding the data generating process (DGP) that are compatible with given moment conditions. The null hypothesis is taken to be rational expectations...

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...

Previous investigators argued that increasing 5-year survival for cancer patients should not be taken as evidence of improved prevention, screening, or therapy, because they found little correlation between the change in 5-year survival for a specific tumor and the change in tumor-related...

This paper provides evidence on the unit root hypothesis and long-term growth by allowing for two structural breaks. We reject the unit root hypothesis for three-quarters of the countries approximately 50% more rejections than in models that allow for only one break. While about half of the...

Each year, thousands of students graduate high school academically unprepared for college. As a result, approximately one-third of entering postsecondary students require remedial or developmental work before entering college-level courses. However, little is known about the causal impact of...

The devolved nature of environmental regulation provides an excellent opportunity for" estimating the effects of regulation on employment, by generating rich variation in regulation" across regions and over time. We exploit this variation using direct measures of regulation and" plant data. We...

Data on health care expenditures, length of stay, utilization of health services, consumption of unhealthy commodities, etc. are typically characterized by: (a) nonnegative outcomes; (b) nontrivial fractions of zero outcomes in the population (and sample); and (c) positively-skewed distributions...

It is common in empirical research to use what appear to be sensible rules of thumb for cleaning data. Measurement error is often the justification for removing (trimming) or recoding (winsorizing) observations whose values lie outside a specified range. This paper considers identification in a...