I'm thinking of playing Carthage. I remember playing them some time back, and one of my more distant provinces (Gades) was losing around 50% of its revenue to corruption. I've never really twigged what factors apply to this, so I'd appreciate a couple of clues.

Is it limited by the management skill of the governor? Or the law level? Or something else?

Are there buildings that will directly control it? Or buildings that will give my governors traits that control it?

Any other advice on limiting it?