Sharp Bounds for the Marginal Treatment Effect with Sample Selection
Abstract
I analyze treatment effects in situations when agents endogenously select into the treatment group and into the observed sample. As a theoretical contribution, I propose pointwise sharp bounds for the marginal treatment effect (MTE) of interest within the always-observed subpopulation under monotonicity assumptions. Moreover, I impose an extra mean dominance assumption to tighten the previous bounds. I further discuss how to identify those bounds when the support of the propensity score is either continuous or discrete. Using these results, I estimate bounds for the MTE of the Job Corps Training Program on hourly wages for the always-employed subpopulation and find that it is decreasing in the likelihood of attending the program within the Non-Hispanic group. For example, the Average Treatment Effect on the Treated is between $.33 and $.99 while the Average Treatment Effect on the Untreated is between $.71 and $3.00.
Cite
@article{arxiv.1904.08522,
title = {Sharp Bounds for the Marginal Treatment Effect with Sample Selection},
author = {Vitor Possebom},
journal= {arXiv preprint arXiv:1904.08522},
year = {2019}
}