The crooks often already have a felony conviction, and are already living with the permanent consequences of that. The only remaining disincentive to crime for them is additional jail time, which can start to be seen as just a cost of doing business - X years for Y dollars.
In not sure the trade is that simple. Everyone I've known that has served time did the crime for one of two reasons:
Most of the people who did financial crimes: Got away with it multiple times and just assumed they wouldn't get caught.
The rest: totally irrational and fueled by mental health problems. Addictions, depression, relationship problems...
I wish we were as good at helping people as we are at isolating and punishing. If punishment was a good deterrent, we wouldn't have roughly .7% of the adult population in jail.
