Recent models of trade with firm heterogeneity predict that opening to trade reduces the number of firms, increases the average size of firms, and decreases firms’ markups. This paper uses a large dataset for 28 manufacturing industries and 46 countries to test these predictions. The...

The use of propensity score models for program evaluation with non-experimental data typically requires the propensity score be estimated, often with a model whose specification is unknown. While theoretical results suggest that estimators utilizing more flexible propensity score specifications...

The use of propensity score methods for program evaluation with non-experimental data typically requires the propensity score be estimated, often with a model whose specification is unknown. While theoretical results suggest that estimators utilizing more flexible propensity score specifications...

We characterize the bias of propensity score based estimators of common average treatment effect parameters in the case of selection on unobservables. We then propose a new minimum biased estimator of the average treatment effect. We assess the finite sample performance of our estimator using...