Professor King, No matter what I try, I continue getting this error message (obs must be between 618 and 936) after which the simulations halt. This message is preceded by: Note: Clarify is expanding your dataset from 618 observations to 1000 observations in order to accommodate the simulations. This will append missing values to the bottom of your original dataset. I've tried with other data sets and I continue to get this message, the number of obseravtions, naturally varies. What can I do to correct this? Thanks, cp -- Clarify mailing list served by Harvard-MIT Data Center [Un]Subscribe/View Archive: http://lists.gking.harvard.edu/?info=clarify