1) Can population average (marginal) models be specified in Mplus rather than conditional RE models?
I'm collecting cross sectional data for individuals (i=100) clustered within neighborhoods (j=40). I'm interested in group effects on individual outcomes and since I won't have variability within a neighborhood at the group level variable, I was looking at using marginal models.
2) Can a variable for the group (ambient air pollution concentrations) be used as a mediator of two individual level variables in the model? Individual measurements are not possible.