RD: Stata module for regression discontinuity estimation
rd implements a set of regression-discontinuity estimation methods that are thought to have very good internal validity, for estimating the causal effect of one explanatory variable in the case where there is an observable jump (discontinuity) in the level of the explanatory variable. Local linear regression is used to construct point estimates. Graphics dictate Stata 8.2 or later. An older version of the software is also included as rd_obs.