I am working with diary data (days nested in persons) and I estimate a two-level interaction model. I wondered if I should include the covariance between the product term and the components as well. Thus, that would be for instance: y ON x m xm; xm WITH x m;
Thank you for your quick reply. I actually ran into another problem. Is there an easy way to calculate cross products from group-mean centered variables? I read some of the previous discussions and they suggested to first GMC the data, save it and then calculate the cross-product using a define command. Is there a new way in the latest Mplus version to do this at once?