I want to model frequency of a social effect by state over several years as potentially predicted by several demographic factors. I have been reading that one is supposed to determine the random effect structure before trying to determine the fixed effects structure. One thing I want to be sure to test for fixed effects is an interaction with time for each fixed effect.
Do I want to just have intercept|State or do I want to look at slope of each possible fixed factor per state, as well. How would I do the latter if I have not yet built the fixed effects portion of the model? Would I also look at fixed:time for each potential fixed effect as random effects?
I want to avoid dredging. I have only 459 points for each variable (9 years, 50 states + DC). However, I also want to be able to contrast model predictions for the full model vs. a fixed-effect only model.