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From |
sjsamuels@gmail.com |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: svyset problem 2: using svy with partially complete surveys |

Date |
Fri, 25 Sep 2009 14:46:27 -0400 |

Calculating "fpc" for the post-stratified totals is unjustified and unnecessary: unjustified, because the theory of fpc's applies only to the original sampling design; unnecessary because the post-stratified "fpc" values will will be, on average, about same the the design fpc values. On Thu, Sep 24, 2009 at 5:46 PM, Michael I. Lichter <mlichter@buffalo.edu> wrote: > Peter, > > Your question is whether we can or should, in theory, correct variance > estimates for the size of the sample relative to the population within each > poststratum, just as is done for "real" strata. It's not a question that > ever occurred to me before, but it does make sense. I don't see why this > could not be done, although it may be mooted by the poststratification > adjustments to variance calculation that Stata does. Perhaps somebody more > knowledgeable than me can answer you properly. > > Also, you said: >> >> An alternative I've considered is to define strata that identify >> unique combinations of lep and gender and then feeding this >> information to the poststratification options in svyset. Problem here >> is that each PSU, school, now overlaps two strata--one for each gender >> in that school--and it's not clear what the FPC numbers should be for >> each strata. Am guessing this arrangement will probably violate >> assumptions behind svy. > > If you were going to create a poststratum-specific FPC, it would be at the > student level, not the school level. The original FPC is at the school level > because that's how you sampled. In creating poststrata defined by student > characteristics, you are in effect pretending that you sampled students, not > schools. Your stratum-specific FPC would be at the student level, so > cross-classification of schools is not a problem. > > As for your missing data problem, either using complete cases only or > following Nick's suggestion about imputation are both probably better > solutions to your problem than performing some analyses on some cases and > other analyses on other cases. > > Michael > * > * 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/ > -- Steven Samuels sjsamuels@gmail.com 18 Cantine's Island Saugerties NY 12477 USA 845-246-0774 * * 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/

**References**:**st: svyset problem 2: using svy with partially complete surveys***From:*Peter Muhlberger <pmuhl1848@gmail.com>

**Re: st: svyset problem 2: using svy with partially complete surveys***From:*"Michael I. Lichter" <mlichter@buffalo.edu>

**Re: st: svyset problem 2: using svy with partially complete surveys***From:*Peter Muhlberger <pmuhl1848@gmail.com>

**Re: st: svyset problem 2: using svy with partially complete surveys***From:*"Michael I. Lichter" <mlichter@buffalo.edu>

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