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From |
Steven Samuels <sjhsamuels@earthlink.net> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Question about svyset command |

Date |
Thu, 19 Feb 2009 08:17:07 -0500 |

Thomas,

Two questions came to mind:

Good luck! -Steve References Cochran, W. G. (1977). Sampling techniques (3ded.). New York: Wiley.

On Feb 19, 2009, at 12:04 AM, thomashcohen@aol.com wrote:

Iâm a beginner Stata user and have a question about the svysetcommand in Stata that I hope someone can help me with.For some background, I'm engaged in a logistic regression modelthat examines the likelihood of either a plaintiff or defendantfiling a post trial motion. The database I'm working with is theCivil Justice Survey of State Courts (CJSSC). The CJSSC providescase level data for all t conclude in a sample of 46 of thenation's 75 most populous counties in 2005. Data are collected onabout 8,000 trials in these 46 counties which are weighted torepresent about 10,500 trials concluded in the nation's 75 mostpopulous counties. I understand that one of the nice features ofStata is that it allows you to take into account the samplingstructure of a dataset when doing logistic regression modeling.Here is the Stata code that I used to take in account the samplingstructure of these civil trial data:svyset sitecode [pweight=bwgt0], strata(strata) fpc(fpc1) || su2,fpc(fpc2)Where Sitecode = County where the civil trial took placeBwgt0 = Weights to weight the data from 46 to the 75 most populouscountiesStrata = Strata where the counties are located. The dataset has 5stratafpc1 = The probability of a county appearing in the sample. Forexample, a county with a weight of 2 would have a 50% probabilityof appearing in the samplesu2 = Unique identifier that identifies the trials that occurred ineach of the 46 countiesFpc2 = 1 for all 8,000 trials disposed in the 46 counties. I gavefpc2 a value of 1 because I wanted to tell Stata that the trialshad a 100% probability of showing up in these 46 counties.I think that I got the part of this programming that deals with thefirst level of the sample design correct. Itâ??s the second levelthat Iâ??m having some problems with At the second level of thesample design, I'm trying to correct for the fact that I have datafor every civil trial concluded in the 46 counties. Basically, Iwant to tell Stata that part of this sample is actually a census ofall trials concluded in the 46 counties in 2005. I understand Statahas a finite population correction command that takes into accountthe census like format of these data. The logistic regressionresults were the same irrespective of whether I used the 1st or 2ndstages in the sample design. I think this is telling me that Statais not correcting for the census like aspect of this sample. Cananyone give me some guidance as to whether I'm correctly takinginto account the sampling structure of these data. In particular, Iwould like to know whether I'm using the fpc2 factor correctly. Anyassistance you could give on this matter would be very muchappreciated.Thanks Thomas Cohen * * 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/

**Follow-Ups**:**Re: st: Question about svyset command***From:*"Michael I. Lichter" <mlichter@buffalo.edu>

**References**:**st: Question about svyset command***From:*thomashcohen@aol.com

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