I have an issue in my data set that looks like this:
ID Year Birth Year
1 2000 1990
1 2002

This issue is that person 1 was born in 1990, but for some reason his interview in 2002 doesn't show his birthdate. Is there a way I can code this so that if your birth year is 1990, this will show up as 1990 for all panel observations of you?
Thank you in advance!