This paper proposes a unified approach to derive sharp bounds on all conventional policy parameters when the instrumental variables (IVs) are potentially invalid. Using a Vine Copula approach, we propose a novel characterization of the identified sets for the marginal treatment effect (MTE) and...

This paper investigates the causal effect of job training on wage rates in the presence of firm heterogeneity. When training affects worker sorting to firms, sample selection is no longer binary but is "multilayered". This paper extends the canonical Heckman (1979) sample selection model - which...

We study some recent developments and challenges in the empirics of the effects of social networks. We focus in particular on researchers' ability to make policy recommendations based on a standard linear econometric model. We examine the potential compatibility between this type of econometric...

We study some recent developments and challenges in the empirics of the effects of social networks. We focus in particular on researchers' ability to make policy recommendations based on a standard linear econometric model. We examine the potential compatibility between this type of econometric...

We study some recent developments and challenges in the empirics of the effects of social networks. We focus in particular on researchers' ability to make policy recommendations based on a standard linear econometric model. We examine the potential compatibility between this type of econometric...