[amelia] Introducing myself and two questions

Hello, I just downloaded Amelia (and Zelig a little while ago). They look great! I'm a statistician/data analyst, mostly working for psychologists, social scientists, doctors, etc. My question: I have a data set with 4 time points. The DV is a count, very overdispersed and right skew ... it's a number of unprotected sexual acts. IV's are marital status, age, income, and highest grade of school. Various patterns of missingness. My questions: 1) Age clearly increases in a known pattern. It doesn't really need to be imputed. Can I make this happen in Amelia, or should I do it separately, before running Amelia? 2) I tried running susanMI.out <- amelia(susan, m = 5, ts = "time", noms = "married", cs = 'id', intercs = T, polytime = 1) and got an error The number of observations is too low to estimate the number of parameters. You can either remove some variables, reduce the order of the time polynomial, or increase the empirical prior. which is clear, but I am not sure what to do here. Thanks for any advice, and thanks to Gary King for writing the software! Peter Peter L. Flom, PhD Statistical Consultant Website: http://www DOT statisticalanalysisconsulting DOT com/ Writing; http://www.associatedcontent.com/user/582880/peter_flom.html Twitter: @peterflom - Amelia mailing list served by Harvard-MIT Data Center [Un]Subscribe/View Archive: http://lists.gking.harvard.edu/?info=amelia More info about Amelia: http://gking.harvard.edu/amelia