I recently uploaded a package to CRAN called `dispmod' which provides functions for modelling dispersion in GLM. In particular, the function `glm.binomial.disp' fits overdispersed binomial logit models following the approach discussed by Williams, D. A. (1982), Extra-binomial variation in logistic linear models, Applied Statistics, 31, 144-148.
I hope this can help you. Luca +-----------------------------------------------------------------------+ | Dr. Luca Scrucca | | Dipartimento di Scienze Statistiche tel. +39 - 075 - 5855278 | | Universita' degli Studi di Perugia fax. +39 - 075 - 43242 | | Via Pascoli - C.P. 1315 Succ. 1 | | 06100 PERUGIA (ITALY) | | | | E-mail: [EMAIL PROTECTED] | | Web page: http://www.stat.unipg.it/luca | +-----------------------------------------------------------------------+ ______________________________________________ [EMAIL PROTECTED] mailing list http://www.stat.math.ethz.ch/mailman/listinfo/r-help
