转自How to beat the Prisoner’s Dilemma in the TV game show Golden Balls

Golden Balls is an amusing British game show. Especially interesting is the final contest which is a version of the Prisoner’s Dilemma.

If you’re never seen the show, here is how it works. Each of two contestants independently chooses to split or steal the final prize. If both choose split, then the prize is divided evenly. If one chooses split and the other steal, the person who steals gets the entire prize. If both choose steal, however, then both walk away with nothing.

Here’s the normal form representation of the game:

How should you play this game?

One contestant had an amazingly brilliant strategy.

**The wrong way to play the game**

Contestants are allowed to discuss strategy before picking split or steal.

Both realize that split gives a fair 50 percent share to each side, but each also sees the advantage of back-stabbing and stealing the prize.

The discussion usually involves the following strategy. Each person tries to convince the other person to split, and they promise to do the same.

I discussed an example of this in a previous post: strategy in Golden Balls.

In that episode, both were promising they would split the prize, but then one person decided at the last minute to steal all the money. She said she was not proud of the decision, but she herself did not want to be cheated.

So trying to split the money in a conventional way doesn’t work. Is there a better strategy?