To use Stata’s time-series operators (l.
, f.
, d.
, etc.), you must first declare the time and panel variables using tsset
, but the CNM is already mi set
, so tsset
won’t work. Run the following before merging the rest of your data (called my_data.dta
in this example) into the CNM:
use cnm1_0.dta, clear
egen cc = group(country)
mi tsset cc year
merge 1:1 country year using "my_data.dta", keep(match master)
Now you’ll be able to use l.
and the rest of Stata’s time-series operators.