““Marriage is a prisoner's dilemma in which you get to choose the person with whom you're in cahoots. This might seem like a small change, but it potentially has a big effect on the structure of the game you're playing. If you knew that, for some reason, your partner in crime would be miserable if you weren't around - the kind of misery even a million dollars couldn't cure - then you'd worry much less about them defecting and leaving you rot in jail.””
