TY - JOUR T1 - What Can Ex-Participants Reveal about a Program’s Impact? JF - Journal of Human Resources JO - J Hum Resour SP - 208 LP - 230 DO - 10.3368/jhr.XL.1.208 VL - XL IS - 1 AU - Martin Ravallion AU - Emanuela Galasso AU - Teodoro Lazo AU - Ernesto Philipp Y1 - 2005/01/01 UR - http://jhr.uwpress.org/content/XL/1/208.abstract N2 - We propose a method for estimating the mean impact of an assigned social program when it is not feasible to do a pre-intervention baseline survey but it is feasible to track ex-participants. In our triple-difference estimator, measured outcome changes are compared between continuing participants and matched ex-participants, after netting out the outcome changes for a matched comparison group who never participated. With sufficient followup observations one can test the joint conditions required for correctly identifying the gains to current participants. We apply the method to a workfare program in Argentina. Significant impacts on participants’ current incomes are revealed. ER -