Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
From | Steve Samuels <sjsamuels@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: Resampling and compare full sample with subsamples |
Date | Tue, 4 Mar 2014 15:38:19 -0500 |
Johannes- I don't get the logic of your approach. Assuming that prevalence rates of responders and non-responders differ, i.e. show "response bias", a comparison of random samples of responders to all responders will provide *no* information on the degree of bias. There are accepted reweighting techniques for evaluating and reducing response bias. See the downloadable references below. If, in fact, you know descriptive statistics for the entire population of schools and for the responding schools, you can make the responding schools more closely resemble not just the sample, but the population. See Stas Kolenikov's -ipfraking- (-findit-) and John D'Souza's -calibrate- (SSC). References: Burns, Shelley, Xiaolei Wang, and Alexandra Henning. 2011. NCES Handbook of Survey Methods. NCES 2011-609. National Center for Education Statistics http://eric.ed.gov/?id=ED521154 Carlson, BL, and Williams, S. 2001. A comparison of two methods to adjust weights for non-response: propensity modeling and weighting class adjustments. Proceedings of the Annual Meeting of the American Statistical Association http://www.amstat.org/sections/SRMS/proceedings/y2001/Proceed/00111.pdf Kreuter, Frauke, Kristen Olson, James Wagner, Ting Yan, Trena M Ezzati-Rice, Carolina Casas-Cordero, Michael Lemay, Andy Peytchev, Robert M Groves, and Trivellore E Raghunathan. 2010. Using proxy measures and other correlates of survey outcomes to adjust for non‚Äêresponse: examples from multiple surveys. Journal of the Royal Statistical Society: Series A (Statistics in Society) 173, no. 2: 389-407. http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1139&context= sociologyfacpub Little, RJ, and S Vartivarian. 2003. On weighting the rates in non-response weights. Stat Med 22, no. 9: 1589-1599, available at http://deepblue.lib.umich.edu/bitstream/2027.42/34860/1/1513_ftp.pdf Wun, L-M, and Ezzati-Rice, T. 2007. Assessment of the impact of health variables on nonresponse adjustment in the medical expenditure panel survey (MEPS). Proc. Surv. Res. Meth. Sect. Am. Statist. Ass 2857-2864. http://www.amstat.org/sections/SRMS/Proceedings/y2007/Files/JSM2007-000336.pdf Steve Steve Samuels Consultant in Statistics 18 Cantine's Island Saugerties NY 12477 USA 845-246-0774 > On Mar 3, 2014, at 10:58 AM, Johannes Thrul <Thrul@ift.de> wrote: > > Dear list, > I am working on a large survey dataset (12,000 individuals clustered in 600 schools) and want to examine, how non-response/non-participation of schools affects prevalence estimates (e.g., alcohol use). My plan is to reduce the sample of schools randomly and systematically (e.g., only exclude large schools) and compare the resulting estimates from the subsamples with the estimates from the full sample. I thought of an approach like this: Reduce the sample size in 10% increments, draw a number of subsamples at every step and compare the estimates. However, I have 2 questions about how to best approach this in Stata: > 1. Drawing subsamples: Should I use a jackknife, bootstrap, or even something entirely different for drawing the subsamples? > 2. Testing: How should I go about testing the results from the subsamples against the full sample? > Any help is greatly appreciated! > Thanks and kind regards, Johannes > > -- > Dr. Johannes Thrul, Dipl.-Psych. > > Wissenschaftlicher Mitarbeiter / Researcher > Präventionsforschung / Prevention Research > > IFT Institut für Therapieforschung / Parzivalstr. 25, D-80804 München / www.ift.de > phone +49 (0) 89 360804 86 / fax +49 (0) 89 360804 69 / e-mail thrul@ift.de > > IFT Institut für Therapieforschung gem. Gesellschaft mbH / Registergericht München HRB 46395 Geschäftsführung: Prof. Dr. Gerhard Bühringer > > * * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/