Suppose they have a written contract, or even an unwritten contract, what enforces the contract for colluding firms or crooks in jail?

假如他们签了一份书面协议,或干脆口头的,他们怎么强制履行呢

耶鲁公开课 - 博弈论课程节选

If I don't, I get locked in jail or they tell me to get out of the country.

如果不缴税，我会被关到监狱,或者被驱逐出境。

耶鲁公开课 - 公正课程节选