Dear Stata-Listers,

I have the feeling that the solution is quite easy. However, I just can't figure it out.

So, I have cross sectional data for regional districts in Germany with differing observations per year, for the years 2012 to 2015.

The variable A is asked in the years 2014 and 2015.

A year district

When:
reg A year
I get beta=60.9

What I would like to do now is set variable A in the year 2013 to A(2014)-60.9 for each district separately.