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From | Austin Nichols <austinnichols@gmail.com> |
To | "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |
Subject | Re: st: svyset command, pweight value? |
Date | Thu, 24 Oct 2013 09:59:23 -0400 |
Mikkel Høiberg <mikkelhoiberg@gmail.com>: The simplest pweight is 1/p, where p is the probability of selection. So if the 1250 surveys were a simple random sample of the 360144 people, and all the 1250 surveys were returned you would define g s1w=360144/1250 for "stage 1 weight" noting in passing that this is not called a dummy variable. But you have nonresponse. If the 635 responses were a simple random sample of the 1250 you could g pw=360144/1250*1250/635 or g pw=360144/635 but I doubt either "stage" is a simple random sample. Nonresponse, in particular, is unlikely to be random. You will want to model the probability of nonresponse as a function of observable characteristics, including age and geography and whatever else you can, then adjust appropriately. Read a book on survey methodology, for starters. On Thu, Oct 24, 2013 at 9:44 AM, Mikkel Høiberg <mikkelhoiberg@gmail.com> wrote: > Dear Stata listers, > > I am workning on survey data, where reveivers of the quesionnaire were > drawn from the total Norwegian population, the total number of which > is known. > The number of questionnaires sent out were stratified by age-decade to > ensure higher total number of responses in the youngest and eldest > part of the population and to correct for expected lower response > rates in these subgroups. > > As far as i understand, I am to use the svyset command for survey data > to prevent falsely low standard deviations and thus false positive > statistical associations. > > I intend to create a dummy variable for the svyset command. > > However: how should this dummy variable be constructed? > > As an example: for women between 40 and 50 years, the total female > population in question is 360.114. 1250 questionnaires were sent out, > 635 received. > Could I code a dummy variable with the value 360144* 635/1250 = > 182.935 for this agegroup? > An then do the same calculations for other subgroups? > Or should I use the inverse value? > Or a third option? > > -- > Your help is very much appreciated! * * 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/