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From | Debs Majumdar <debs_stata@yahoo.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: sampling using matching variables |
Date | Tue, 17 Aug 2010 15:43:19 -0700 (PDT) |
@Steve: I don't. But 2 of the reviewers wanted it as a part of sensitivity analyses. Thanks anyways. -Debs ----- Original Message ---- From: Steve Samuels <sjsamuels@gmail.com> To: statalist@hsphsun2.harvard.edu Sent: Tue, August 17, 2010 9:52:46 AM Subject: Re: st: sampling using matching variables Why do you require 1-1 matching? There is more information (= greater power, smaller standard errors) in analyses of matched sets with >1 person from each group. If you insist, despite this advice, then let "mset" be the variable that identifies a matched set -will differ from command-to-command (I like -cem- myself): ********************************************** set seed 12345 // choose your own seed gen u=uniform() bysort mset race (u): keep if _n==1 ********************************************* Steve -- Steven Samuels sjsamuels@gmail.com 18 Cantine's Island Saugerties NY 12477 USA Voice: 845-246-0774 Fax: 206-202-4783 On Tue, Aug 17, 2010 at 12:29 PM, Christopher Swearingen <christopher.swearingen@gmail.com> wrote: > Debs, > > I have used the contributed psmatch2, a propensity scoring method, to > match groups on various covariates. > > findit psmatch2 > > *** 1-1 age only matching > psmatch2 nonwhite age, noreplacement > gen age_matched = _weight > > *** 1-1 age & education matching > psmatch2 nonwhite age education, noreplacement > gen age_education_matched = _weight > > *** 1-1 age & education & gender matching > psmatch2 nonwhite age education gender, noreplacement > gen age_education_gender_matched = _weight > > ~c > ________________________________________________________ > Christopher Swearingen, Ph.D. > Assistant Professor of Pediatrics and Biostatistics > University of Arkansas for Medical Sciences > Department of Pedatrics > One Children's Way, Slot 512-43 > Little Rock, AR 72202 > > http://www.arpediatrics.org/research/biostatistics > > > > On Mon, Aug 16, 2010 at 10:27 PM, Debs Majumdar <debs_stata@yahoo.com> wrote: >> Hi, >> >> I have a dataset of around 1000 people where 750 are whites and 250 are >> non-whites. I have variables for age (35-75), education (0-20) and gender (0 >or >> 1). Also in the dataset I have item responses to 10 questions for each of >these >> 1000 people. >> >> I would like to create dataset(s) where one white is matched with a non-white >> person in terms of age only, age and education, and age,education and gender. >> >> Initially, I tried matching on age only. But then for some cases I end up with >>3 >> >> whites and 1 non-white for the same age category. At that time I would like to >> drop any 2 of those 2 at random in the new dataset so that the matching is >> always 1-1. How do I do that? >> >> I have tried using cem, vmatch etc. but didn't get what I want. >> >> Thanks, >> >> -Debs >> >> >> >> * >> * 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/ >> > > * > * 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/ > * * 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/ * * 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/