Stata stops the following loop with a "not sorted" line after the
"sort id difa`i'" command (not after the subsequent command, after the
sort command). What am I missing? Thanks!!
forvalues i = 1/5 {
by id treated: gen var_a`i'=.
replace var_a`i'=ln_var if ante_`i'==1
by id treated: egen var_a`i'_mean=mean(var_a`i')
gen difa`i'=.
replace difa`i'=var_a`i'_mean - var_a`i'_mean[_n-1] if id==id[_n-1]
replace difa`i'=. if difa`i'==0
sort id difa`i'
replace difa`i'=difa`i'[_n-1] if difa`i'==. & id==id[_n-1]
}
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