Estimation for a combination of countries

[Olivia Emma]

Hi I have a data on number of countries

and I want to run the regression on combination of countries please how I can do that Please.

country1 country2 country3 country4 country5


reghdfe y x1 x21, a(yearofbirth)




I want to run regression for


country1 country2 country3 country4

country1 country2 country3 country5

and so on for possible combinations


Thanks

[Clyde Schechter]

How many countries do you have? There are 195 in the world. If you have even only 100 in your data, there are 75,287,520 possible combinations of 5 countries from among those 100. Even if your data set is restricted to the 44 countries of Europe, there are 1,086,008 such combinations.

In short, unless you have a very small number of countries, this plan sounds like a non-starter to me.