I have an analysis that involves dyadic data. Taking David Kenny's advise, each member has been entered twice in the data set (what he refers as pairwise data entry). To adjust for the sample size, I need to weight each case by .5 and am looking for the correct Mplus syntax that allows me to do that. Any insights from you would be helpful.
It is not necessary to do this trick. You can either have your data in the long format and have the cluster variable be the dyad or in the wide format where each member of the dyad has their own variables and multivariate modeling takes care of the non-independence of observations.