olivija18

Hello all Stata-Kings/Queens,

I am trying to merge two datasets, but they don't have a unique ID.
My dataset looks like this

ctry year commodity prod
Argentina 1996 Broccoli 300
Argentina 1996 Cabbage 200
Argentina 1997 Broccoli 100
Brazil 1996 Broccoli 100

I have 14 years of data, 89 countries and 47 products (all vertically listed in the dataset)

I would like to replace missing values in the above dataset coming from few other datasets.

How can I create a unique ID that will be the same in all datasets.
For, example ID=1 in all datasets by group (ctry, year, commodity)

Thank you all so much!!!!