Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down on April 23, and its replacement, statalist.org is already up and running.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: strata with single sampling units


From   sjsamuels@gmail.com
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: strata with single sampling units
Date   Thu, 4 Mar 2010 14:04:25 -0500

" Would I be safe in assuming that one would use weight and PSU, and ignore
strata in this case? "

No. Do not ignore the stratum specification.  By placing certainty
units in their unique strata you ensure that they contribute nothing
to the between-PSU component of variance.  If the purpose of your
study is to describe the population, then the first stage fpc for the
certainty units should be 1.

Steve Samuels
sjsamuels@gmail.com
18 Cantine's Island
Saugerties NY 12477
USA
845-246-0774



> When I went back to the documentation it is stated that the study
> used a multistage stratified design in which primary sampling units
> (PSUs) were stratified according to certain sociodemographic criteria. The
> sampling
> frame for housing units is the Census 2000/2001 Supplementary Survey
> (C2SS) and that
> for group quarters is the Census 2000 Group Quarters Inventory. The C2SS
> sample of
> 655 PSUs was selected at the first stage, including 401 self-representing
> (SR) and 254
> non-self-representing (NSR) PSUs. All SR PSUs were selected with
> certainty. For the
> NSR sample, two PSUs were selected per stratum, with probability
> proportional to the
> size of the estimated 1996 population of the stratum.  NOTE: Sample was
> included from each of the 655 PSUs.
> However, to prevent potential respondent disclosure, some PSUs were
> collapsed so that the final
> data file shows 435 PSUs, 305 being SR and 130 being NSR.
>
> So there are 305 strata with one PSU.  Final sample is 43,093.
>
> Would I be safe in assuming that one would use weight and PSU, and ignore
> strata in this case?  No other design variables are provided.  Doing
> things this way seems to replicate SEs in the published tables  -- at
> least the few I tried to replicate.

*
*   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/


© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index