Hello!

I am using Stata16 and I am running simple wage regressions and decomposing the gender wage gap.

I am trying to test the robustness of my regression specifications. My data is only between the ages of 16-64, however I would like to run this regression for a different sample (e.g 25-59 years) and compare the results between the 2 regressions to see if the regression is robust or not.

Current code is:

Code:
  reg lghourpay age agesq first uppersecond lowersecond third degree alevel married female Q2 Q3 Q4
Question 1: How do I restrict the ages and run the regression purely for ages between 25-59 when my data is between ages 16-64?

Question 2: In order to compare the results between the 2 regressions, would an F-test be best? If so, how would I run a F test between the 2 regressions of different age groups?

Thanks!