We recommend the immediate universal adoption of cloth facemasks, including homemade, and accompanying policies to increase the supply of medical masks for health workers. Universal adoption will likely slow the spread of the COVID-19 virus by reducing transmission from asymptomatic individuals....

In this paper, we explore Bayesian inference in models with many instrumental variables that are potentially weakly correlated with the endogenous regressor. The prior distribution has a hierarchical (nested) structure. We apply the methods to the Angrist-Krueger (AK, 1991) analysis of returns...

In this paper we analyze estimation of coefficients in regression models under moment restrictions where the moment restrictions are derived from auxiliary data. Our approach is similar to those that have been used in statistics for analyzing contingency tables with known marginals. These...