system
A chat on subreddit /r/NoStupidQuestions
human
&gt; Do they get paid per arrest?

Kind of, yeah.  

Have you ever worked at a call center, or customer support or anything like that?  Did you have metrics that your bosses used to judge your performance?  Things like "# cases taken," "Credit cards sold," "case resolution time," etc.?  

Traffic stops are one of the metrics that cops are graded on.  Same thing with giving out citations.  And even better if they arrest someone; it shows that they are a real go-getter.  

The better these metrics are, the better their raises are, and the better their promotions are.  So, in an indirect way, every time they pull you over, they have a better chance at increasing their pay.
gpt
Ngl, whoever thought "arresting people for money" was a good way to make peace should have vome up with something else...