I'm trying to figure out how to use lmer to fit models with factors that have some nesting and some non-nested groupings. For example, in this paper: http://www.stat.columbia.edu/~gelman/research/published/parkgelmanbafumi.pdf we have a logistic regression of survey respondents' political preferences (1=Republican, 0=Democrat), regressing on sex, ethnicity, state (51 states within 5 regions), 4 age categories, and 4 education categories. I'd like to include states (nested within regions), and also age, education, and age x education. (That is, 5 batches of varying coefs: 50 states, 5 regions, 4 age categories, 4 education categories, and 16 age x education categories.) The age x education factor is kinda tricky because it's connected both to age and to education.
I'm thinking of a model like this: lmer (y ~ black*female + (1 | state) + (1 | region) + (1 | age) + (1 | edu) + (1 | age.edu), family=binomial(link="logit")) (Here, I'm thinking of age.edu as a variable with 16 levels.) Anyway, it blows up when i try to put in these nested things. I read Doug Bates's article in R-news and there seems to be a way of doing nested groupings (unfortunately, I can't quite figure out how to do it), but I don't see any references to situations such as age, edu, and age*edu . For the article, we used Bugs, which is fine, but I'd like to see how far I can take it using lmer. I could kludge it by, for example, including age, edu, and region as unmodeled factors: lmer (y ~ black*female + (1 | state) + factor(region) + factor(age) + factor(edu) + (1 | age.edu), family=binomial(link="logit")) but I'd like to do the full multilevel version. Thanks! Andrew -- Andrew Gelman Professor, Department of Statistics Professor, Department of Political Science [EMAIL PROTECTED] www.stat.columbia.edu/~gelman Tues, Wed, Thurs: Social Work Bldg (Amsterdam Ave at 122 St), Room 1016 212-851-2142 Mon, Fri: International Affairs Bldg (Amsterdam Ave at 118 St), Room 711 212-854-7075 Mailing address: 1255 Amsterdam Ave, Room 1016 Columbia University New York, NY 10027-5904 212-851-2142 (fax) 212-851-2164 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html