Unconditional quantile treatment effects are difficult to estimate in the presence of fixed effects. Panel data are frequently used because fixed effects or differences are necessary to identify the parameters of interest. The inclusion of fixed effects or differencing of data, however,...

This paper introduces an unconditional quantile regression (UQR) estimator that can be used for exogenous or endogenous treatment variables. Traditional quantile estimators provide conditional treatment effects. Typically, we are interested in unconditional quantiles, characterizing the...

This note discusses partial identication in a nonparametric triangular system with discrete endogenous regressors and nonseparable errors. Recently, [Jun, Pinkse and Xu (2011, JPX). Tighter Bounds in Triangular Systems. Journal of Econometrics 161(2), 122-128] provides bounds on the structural...

Structural economic models allow one to analyze counterfactuals when economic systems change and to evaluate the well-being of economic agents. A key element in such analysis is the ability to identify the primitive functions and distributions of the economic models that are employed to describe...

Instrumental Variables (IV) methods identify internally valid causal effects for individuals whose treatment status is manipulable by the instrument at hand. Inference for other populations requires homogeneity assumptions. This paper outlines a theoretical framework that nests causal...

This paper analyzes conditions under which various single-equation estimators are asymptotically normal in a simultaneous equations framework with many weak instruments. In particular, our paper adds to the many instruments asymptotic normality literature, including papers by Morimune (1983),...

We examine instrumental variables estimation in situations where the instrument is only observed for a sub-sample, which is fairly common in empirical research. Typically, researchers simply limit the analysis to the sub-sample where the instrument is non-missing. We show that when the...

Many empirical studies specify outcomes as a linear function of endogenous regressors when conducting instrumental variable (IV) estimation. We show that tests for treatment effects, selection bias, and treatment effect heterogeneity are biased if the true relationship is non-linear. These...

An emerging literature on the geography of bohemians argues that a region’s lifestyle and cultural amenities explain, at least partly, the unequal distribution of highly qualified people across space, which in turn, explains geographic disparities in economic growth. However, to date, there...

An emerging literature on the geography of bohemians argues that a region's lifestyle and cultural amenities explain, at least partly, the unequal distribution of highly qualified people across space, which in turn, explains geographic disparities in economic growth. However, to date, there has...