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From | "Ariel Linden, DrPH" <ariel.linden@gmail.com> |
To | <statalist@hsphsun2.harvard.edu> |
Subject | re: st: Manually compute IPTW for PS matching? |
Date | Fri, 16 Mar 2012 10:56:05 -0400 |
Pete, what you are attempting to do doesn't make much sense. 1:1 matching results in an "average treatment on the treated" (ATT) estimator. You then want to take this matched sample - which has just been "adjusted" - and then adjust it to an "average treatment effect" (ATE) estimator? You'd use the inverse probability of treatment weight (IPTW) on the whole population after estimating the propensity score on that population. The IPTW will then give you an ATE estimate. To calculate the IPTW: gen ipt = cond(treatvar, 1/propvar, 1/(1-propvar)) Ariel Date: Fri, 16 Mar 2012 13:03:54 +0700 From: TA Stat <tastat@gmail.com> Subject: st: Manually compute IPTW for PS matching? Dear All This is a simple question. After run psmatch2 command (1:1 matching), I got pscore, treated, support, weight, n1, nn, pdif variables. Do I have to manually calculate IPTW? Is any recommended step-by-step illustration of PS matching in Stata available? Thanks Pete * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/