Robinson's square root of N consistent semiparametric regression estimator in Stata

In this article, we describe Robinson's (1988, Econometrica 56: 931-954) double residual semiparametric regression estimator and Hardle and Mammen's (1993, Annals of Statistics 21: 1926-1947) specification test implementation in Stata. We use some simple simulations to illustrate how this newly coded estimator outperforms the already available semiparametric plreg command (Lokshin, 2006, Stata Journal 6: 377-383).