Hello all I'm moving back and forth between stata and R at the moment - of course, using R whenever possible :-)
I'm running conditional logits on some panel data and I get slightly different results and different N in the two programs. In R I run clogit(trans.dem ~ I(avg.gle_rgdp.500/gle_rgdp) + log(gle_rgdp) + timesince.dem + I(timesince.dem^2) + timesince.dict + I(timesince.dict^2) + p_polity2 + I(p_polity2^2) + strata(ccodecow) + cluster(ccodecow), method="approximate", data=univ) and I get an n of 3747. In Stata, I run clogit trans_dem avg_gle_rgdp_ratio loggle_rgdp timesince_dem timesince_demsq timesince_dict timesince_dictsq p_polity2 pol2sq, group(ccodecow) vce(cluster ccodecow) which I hope is the same model. I get a message "29 groups (935 obs) dropped because of all positive or all negative outcomes", and an n of 2812. Also, the coefficients are slightly different. I understand why Stata is dropping the groups with all outcomes the same... this is inevitable in a conditional logit, right? Is R doing the same? And what might be the cause of the difference in coefficients? Cheers David Hugh-Jones Post-doctoral Researcher Max Planck Institute of Economics, Jena http://davidhughjones.googlepages.com [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
