Hi!

I have a cross-sectional time-series dataset and would like to add some firm-specific information from another dataset.


The variables I intend to use for merging is a company identifier (ds_code) and year. Unfortunately I have no idea why I receive 0 matched observations I checked for duplicates and the format should be fitting as well?


. merge m:1 ds_code year using "C:\Users\Desktop\Stata - Analysis\All_Financials.dta"
(note: variable ds_code was str6, now str7 to accommodate using data's values)

Result # of obs.
-----------------------------------------
not matched 1,992,565
from master 3,998 (_merge==1)
from using 1,988,567 (_merge==2)

matched 0 (_merge==3)
-----------------------------------------

Can anyone give me an advice from outside what might be the cause for this problem?

Thanks a lot!