jump to navigation

The prosecutor’s dilemma May 25, 2015

Posted by Ezra Resnick in Game theory.
add a comment

“Here’s the deal: We’ve got enough evidence to convict you and your partner of a misdemeanor right now, and you’d each get two years in prison. Now, if both of you come clean, and confess to the felony I know you committed, you’ll each get three years. Why would you do that, you ask? Well, my colleague is in the other room right now making the same offer to your partner. If he signs a confession and you don’t, we let him off with one year and give you four! Of course, if you sign a confession and he doesn’t, the reverse applies. Now, if you think about it rationally, you’ll see that —”

“Yeah, yeah — I’m better off confessing no matter what my partner does, and we both end up doing three years — I’m familiar with the Prisoner’s Dilemma. Do you think I’m stupid? Listen up, cause here’s the deal: I’ll confess, but I only serve one year — no matter what my partner does. If you refuse, then I confess nothing, and I go public with the story of how you tried to use Game Theory to bully me into signing a false confession. Oh, and did I mention that my partner is making the same offer to your colleague in the other room right now? Do you want your colleague to walk away with a felony conviction, while you’re left to defend misconduct charges on your own? Think about it rationally…”

John Nash 1928-2015

John Nash