Missing Treatments

Abstract

This article analyzes the problem of identifying a treatment effect with imperfect observability of the treatment received by the population. Imperfect observability may be due to item/survey nonresponse or to noncompliance with randomly assigned treatments. I derive sharp worst-case bounds that are a function of the available prior information on the distribution of missing treatments. Under the assumption of monotone treatment response, I show that prior information on the distribution of missing treatments is not necessary to get sharp informative bounds. I illustrate the results with an empirical analysis of drug use and employment using data from the National Longitudinal Survey of Youth.