Hello All, I am trying to estimate a generalized linear model using a single dummy variable (bilat). I want to use contr.sum, in which (please correct me if I am wrong) the implicit coefficient on the contrast equals the negative of the sum of all estimated coefficients. I cannot get the contrast to work correctly. The implicit coefficient is way to large (I checked this using the desmat - option dev - package in Stata). I do: contrasts(bilat) <- contr.sum(levels(bilat)) mod_1 <- gamlss(d ~ bilat, family=BEINF, data=df) but this problem is not specific to gamlss. The same problem occurs also, e.g. in contrasts(bilat) <- contr.sum(levels(bilat)) mod_2 <- lm(d ~ bilat, data=df) What am I doing wrong? Thank you for help! Serguei ________________________________________ Austrian Institute of Economic Research (WIFO) P.O.Box 91 Tel.: +43-1-7982601-231 1103 Vienna, Austria Fax: +43-1-7989386 Mail: Serguei.Kaniovski@wifo.ac.at http://www.wifo.ac.at/Serguei.Kaniovski [[alternative HTML version deleted]]