Help: Generating a new variable on a subsample

[Joh Sko]

Hello!

I am a beginner in Stata.

My problem:
I have a selection of countries in my dataset and I want to do a regression on only a subset of these countries.
In my case, my data contains the countries of the world, but I only want my regression to cover the region of North Africa.
But I am unable to figure out the exact command for this.

So basically I want to do something like this:

regress Y-variable X-variable if country_name == "Tunisia", "Egypt", "Morocco", "Tunisia", "Algeria", "Libya", "Sudan"

What am I missing here?



//Thank you

[Nick Cox]

regress Yvariable Xvariable if inlist(country_name, "Tunisia", "Egypt", "Morocco", "Algeria", "Libya", "Sudan")

[Joh Sko]

regress Yvariable Xvariable if inlist(country_name, "Tunisia", "Egypt", "Morocco", "Algeria", "Libya", "Sudan")

Thank you.

Another quick question. I want to only include years from 2000 until today in the regression.
Thus, I have done the following:

gen current_era = year if year >= 2000

How do I perform the regression using only this time period?
I.e. so that the regression is applied to cases that follow the current_era variable.



Thank you for the help.

[Nick Cox]

You can just regress using the new variable. But you don't need a new variable

regress ... if year >= 2000 ...

should work where ... is everything else you want to say.

Detail: >= 2000 includes missing values too, so watch out.