A large literature focuses on the use of propensity score methods as a semi-parametric alternative to regression for estimation of average treatments e¤ects. We show here that the classic regression based estimator of counterfactual means studied by Alan Blinder (1973) and Ronald Oaxaca (1973) constitutes a propensity score reweighting estimator based upon a linear model for the conditional odd...

After performing a randomized experiment, researchers often use ordinary least-square (OLS) regression to adjust for baseline covariates when estimating the average treatment effect. It is widely known that resulting confidence interval valid even if linear model misspecified. In this article, we generalize conclusion covariate adjustment with nonlinear models. We introduce an intuitive way any...

There is now fairly substantial evidence of a socioeconomic gradient in low birth weight for developed countries. The standard summary statistic for this gradient is the concentration index. Using data from the recently published Growing Up in Ireland survey, this paper calculates this index for low birth weight arising from preterm and intrauterine growth retardation. It also carries out a dec...

Using data from the 2000 U.S. Census, the authors explore two alternative explanations for the sexual orientation wage gap: occupational sorting, and human capital differences. They find that lesbian women earned more than heterosexual women irrespective of marital status, while gay men earned less than their married heterosexual counterparts but more than their cohabitating heterosexual counte...