That code works for me. Have you tried restarting R? Jeremy On 20 Apr 2008, at 16:46, Laurence Tai wrote: Hi all, I would like to check my answers using the negative binomial distribution with Zelig, but when I try to fit the negative binomial, I end up with the following error: z.2b <- zelig(conflu ~ ppid + sumil, model = "negbin", data = ussu) Error in poisson(link = log) : unused argument(s) (link = .Primitive("log")) Strangely, I got it to work once before, but then it stopped working once again. If anyone knows why I might be getting this error, I would appreciate any suggestions. Thanks, Laurence _______________________________________________ gov2001-l mailing list gov2001-l at lists.fas.harvard.edu http://lists.fas.harvard.edu/mailman/listinfo/gov2001-l Dr Jeremy Hodgen Senior Lecturer in Mathematics Education King's College London Department of Education and Professional Studies Franklin-Wilkins Building Waterloo Bridge Wing 150 Stamford Street London SE1 9NH Tel: 020 7848 3102 Fax: 020 7848 3182 E-mail: jeremy.hodgen at kcl.ac.uk _______________________________________________ gov2001-l mailing list gov2001-l at lists.fas.harvard.edu http://lists.fas.harvard.edu/mailman/listinfo/gov2001-l