Some folks are surprised to learn that cheating is extremely common. I mean, it’s the norm.
On the other hand, even though our allegedly expect or require us to report all incidents of academic misconduct, faculty generally aren’t doing this. What’s up with that?
Instead of writing about it here, I wrote about it for the Chronicle of Higher Education. If that link gives you a paywall, then this one with Chronicle Vitae should work for you.
Small Pond Science 
I’m an assistant professor at a fancy private university. When I started, I was assigned a teaching mentor. First and only meeting, he told me that he had only one piece of advice: never report a student for teaching, because it was just too much work.