Hi,

I am using Stata 16.1, and have the following (general) issue. I want to drop duplicate observations of one variable (educ) from my dataset but conditioned on another variable (year).
I've found an online dataset, such that it may be easier to talk about. First up I apologize that I am new Stata.

My problem: I want to drop all duplicates of educ for each corresponding year (72 & 74). This means I do not want educ's value to enter for year 72 if it's value has already been observed.
Here is what I've tried do to:

use http://fmwww.bc.edu/ec-p/data/wooldridge/fertil1
keep if year == 72 | year == 74
drop if educ == educ[_n-1] & (year == 72 | year == 74)

The problem:
I am not dropping all duplicates of educ

Any suggestions would be appreciated