Hello,

I would like to ask a more general econometric (and not specific Stata code) question.
I am using the package synth and am wondering which pre-treatment periods to include.

My preferred specification would basically (I will add covariates though) be:

synth pop pop pop(1960), trunit(244) trperiod(1970)

Is it possible to add both "pop" (so the average of pre-treatment values will be used) and "pop(1960)" as predictors?
FYI: My periods are: 1933, 1939, 1950, 1960 (pre-treatment) and 1970 and 1980 (post-treatment).

Best regards,
Götz