Hello,
I am currently working on a paper where I use one-shot survey data from 2006
and 2008 (repeated cross-sections, exact same variables) and, although they
are supposed to be random samples drawn from the same population, there is
considerable multivariate imbalance on demographic variables. Thus, I used
CEM on the pooled sample (with year as "treatment") to make the samples
comparable:
UNWEIGHTED MEANS
year education male age urban
2006 8.572 0.493 37.611 0.792
2008 8.269 0.495 40.841 0.692
Multivariate L1 distance: .34852375
CEM WEIGHED MEANS
year education male age urban
2006 8.204 0.492 40.278 0.700
2008 8.256 0.492 40.696 0.700
Multivariate L1 distance: 2.355e-15
My question is whether it makes sense to run separate regressions for 2006
and 2008 using the respective CEM weights obtained from the pooled sample.
Hope you can help. Thanks!
Reynaldo T. Rojo Mendoza
Ph.D. Student
Department of Political Science
University of Pittsburgh