Hey!

Unfortunately I could not find any answers to my question in previous posts.

I am working with panel data and need to fix certain values. Let me give a brief example:

I want to fix the value "education years" for all my individuals (id) in the dataset with age>40. Is there any simple way to d this?
In the end I would end up with individuals who's education years do not change anymore after age 40, but stay constant.

What I have:
ID EDUCATION (years) AGE
1 12 36
1 12 37
1 12 38
1 12 39
1 13 40
1 14 41
1 14 42
1 14 43
1 15 44
What I need is:
ID EDUCATION (years) AGE
1 12 36
1 12 37
1 12 38
1 12 39
1 13 40
1 13 41
1 13 42
1 13 43
1 13 44
Thank you in advance, sorry if it is too trivial.. but I am stuck with it.