Check if id is different for duplicate observations within group

[Henry Strawforrd]

The setup is as in the example below. There are individuals (referenced by id) observed over time (referenced by t) who can have one or more jobs (jobid). The number of jobs is the number of rows per individual and time period and is available as a variable (jobs).

I want to check whether for an individual with more than one job in a time period, the jobid's are also different. In the example below this is the case for id=1, but for id=2 it is not in t=2. There the person has two jobs but both have the id =1.

input id t jobid jobs
1 1 1 2
1 1 2 2
1 2 1 2
1 2 2 2
2 1 1 1
2 1 2 1
2 2 1 2
2 2 1 2
end

[Øyvind Snilsberg]

bys id t (jobid): gen wanted = jobid[1]!=jobid[_N]

[Nick Cox]

This is an FAQ https://www.stata.com/support/faqs/d...ions-in-group/