Did you ever find a response to the question about STATA Output from CEM- matched observations with missing strata? We are finding the same problem with our data.  None of the matching variables have missing data, yet many of the observations are being assigned to a “missing” stratum (complete with CEM weights for the missing stratum).

Any insights?

Thanks!

Stephanie Moulton

Associate Professor and Director of Doctoral Studies

John Glenn School of Public Affairs

The Ohio State University

http://glenn.osu.edu/faculty/glenn-faculty/moulton/