"Frontline" ran an episode some years back where they investigated some dental clinics that did astonishing numbers of unnecessary major dental operations.

It turns out that the government had a program that paid for these operations when performed on poor people. So the clinics would convince their customers that they needed major dental work, then would do the work and bill the government. The clinics were totally specialized just for this.

"Frontline" pinned the blame on the clinics, sort of "how could the do that". Of course, they're right. But blaming the clinics doesn't work, because the actual problem was the government set things up so that the rise of clinics to exploit the rules was legal and inevitable.

You're now faced with the problem of crafting a bureaucratic rule to define a "necessary" major dental operation. Of course, it's impossible, and the same problem as "management by metrics".