This paper provides a review of methodological advancements in the evaluation of
heterogeneous treatment effect models based on instrumental variable (IV) methods. We …

This paper develops a specification test for instrument validity in the heterogeneous
treatment effect model with a binary treatment and a discrete instrument. The strongest …

We consider the identification of the average treatment effect in models with continuous
endogenous variables whose impact is heterogeneous. We derive a testable restriction that …

Instrumental-variable (IV) estimation is an essential method for applied researchers across
the social and behavioral sciences who analyze randomized control trials marred by …

We propose a method for using instrumental variables (IV) to draw inference about causal
effects for individuals other than those affected by the instrument at hand. Policy relevance …

Among econometricians, instrumental variable (IV) estimation is a commonly used
technique to estimate the causal effect of a particular variable on a specified outcome …

ABSTRACT A growing literature on within-study comparisons (WSC) examines whether and
in what context nonexperimental methods can successfully replicate the results of …

Traditional instrumental variable estimators do not generally estimate effects for the treated
population but for the unobserved population of compliers. On the other hand, when there is …

This note provides a simple exposition of what IV can and cannot estimate in a model with
binary treatment variable and heterogenous treatment effects. It shows how linear IV is …

This article develops an empirical balancing approach for the estimation of treatment effects
under two-sided noncompliance using a binary instrumental variable. The method weighs …