* This is not a prisoner’s dilemma. I would definitely use it in class if I were still teaching game theory, but I wouldn’t do it anywhere near the prisoner’s dilemma so as not to confuse the students. (In fact I wouldn’t let them visit this blog at all.)

* I think the problem with “paradoxical” games like the finitely repeated prisoner’s dilemma etc. is not the assumption of rationality, but the obsession with equilibrium outcomes. (I grant you it’s a little trickier when there’s a uniquely rationalizable outcome, which is a stronger condition than a game just having a unique Nash equilibrium. Sorry for the jargon but I’m in a rush.) For anyone intrigued by my claim, I elaborate here.

* I’m not going to take the time to watch it again right now, but did that girl actually say she was going to pick Split? The only thing I remember vividly is her acting as if she’s worried he’s going to steal, and making him promise. I think liars do that a lot; they try to minimize the actual lying. So whenever Senator Obama said, “I have said repeatedly during the campaign that my position is…” I thought he was saying what wasn’t his position. I.e. he only had to lie that first time, and then subsequent to that event, he could truthfully say, “I have repeatedly said…”
 

that girl actually say she was going to pick Split

I guess not. But she does comfort him wrt the social sanctions: "everybody who knew me would be disgusted if I stole".
 

Very cool game show. All she said was "theres no way I could, everyone I knew would be disgusted". Thats an interesting connection to politics, definitely true.
 

BlackSheep, you're proving my point. She put on a really good show, by saying plenty of things that were perfectly true.

He was the one who quite explicitly swore to her (several times I think) that he wasn't going to steal.
 

BTW I only watched it the one time; I'm not claiming that she literally never lied; maybe she did. But my point is, she spent all of her energy diverted everyone away from her lying.

What really clinched this type of analysis for me was when I watched some real-life crime show and they asked the husband if he killed his wife (or whatever), and he just said, "The thing no one ever considers, is that I was a victim in this too."

I.e. he didn't actually deny that he killed his wife, he tried to get everyone to start sobbing because he was a widower. So I think he did it.

Of course, when I encounter a seriously smooth liar, I will be in trouble.
 

A fat ugly bald man and a thin attractive blond woman. I would think that guy has probably had this happen many times before.
 

Halfway in I was pretty sure she was going to do him in. Though probably due to thinking there wouldn't be much point in posting the video if it turned out another way.

Can anyone recommand a good intro to game theory? I'm feeling intrigued but ignorant ...
 

Connie,

I was completely shocked, but I realized it was because Scott Sumner had titled his post "Proud to be human" or something like that. So I'm watching it, thinking Scott's point is that "irrational" human emotions can allow us to transcend games with bad incentives.

But no, Scott is proud we are a bunch of thieves. I suspect this explains his monetary recommendations.
 

I could see this coming too, just before the end, in the way she blinked.

This is probably as good a point as any to draw a link to Elinor Ostrom and what her research shows about how people behave when the game is not one-off.

Communities develop trust, rules and enforcement mechanisms that allow them to avoid a destructive use of common pool resources:

http://mises.org/Community/blogs/tokyotom/archive/2009/10/16/elinor-ostrom-austrian-praise-for-the-nobel-laureate-and-a-reprise-of-my-posts-on-her-thoughts-on-how-human-communities-successly-manage-commons.aspx

It`s when governments get a longer term, and realithe way that people can`t transact with each other in an enforceable way, leading to destructive (immediate self-interest over long-term values and over neighbors) use.

It was interesting here that both participants talked about the longer term, and the winner felt bad about her own behavior. Actually good signs about how humans want to cooperate - like the recyclers whom Penn & Teller so mercilessly derided.

(Steps off soabox)
 

Bob-

The game show was made in the US under the title "Friend or Foe" ... different way to accumulate wealth in the game but the same choice to "split or steal" at the end.

I'm curious as to why you don't consider the game a "prisoner's dilemma" scenario. Care to elaborate?
 

TokyoTom, I bet that girl works for Exxon.

M4Liberty: Well the technical reason is that picking "steal" is only weakly dominant, not strictly dominant. E.g. the plays you saw occur in the game, constitute a Nash equilibrium, if we assume people just care about personal payout. (Of course people don't just care about that, but then again presumably some prisoners feel bad about screwing over their accomplice too, and that's not put into the payoff matrix of the standard prisoner's dilemma.)

Beyond the technical difference, I think there's an important psychological (or something) difference, arising from this small technical difference. If I were playing this game, I would always Share. If I got screwed over and my friends and relatives complained to me afterward that I was a sucker, I could point out, "Given that the other person was going to 'steal,' I had no hope of getting any money. No matter what I did, I was getting $0. So I picked 'Share' hoping the other person would too. I would feel awful if I picked 'steal' just to spite the other person, whom I thought was going to pick 'steal,' and then it turned out that person actually picked 'share.'"

In contrast, if each person got, say, 10% of the pot if both picked "steal," but you got 0% if you picked 'share' when the other picked 'steal,' then it would be a true prisoner's dilemma, and it would be a lot harder to "do the right thing" since on the margin, it would cost you.
 

Bob-

Thanks for the quick reply... I actually just did some googling and figured out most of the answer for myself regarding the payoff structure.

Also, being a cold hearted bastard, I hadn't really considered the "psychological (or something)" differences to the game.

I used to watch Friend or Foe quite a bit when it was on here in the States and -- from memory -- Women picked "Foe" fairly regularly when they were playing against men. Especially when there was an attractiveness differential greater than X.

I came to the conclusion that if I were ever on the show ... I'd pick foe if I were playing against a woman and friend if I were playing against a guy.
 

Bob is right, this isn't a true prisoner's dilemma scenario (and nice explanation, too).

Like a few others, I could tell half-way through what she was going to do, but I do have a slightly different take on it, I think. She clearly did her very best not to tell an outright, verbal lie while they were assuring each other of their intentions, but I noted in the interview afterwards that she mentioned getting the short end of this game once before, and I don't think she did this with the intention to steal, but with the intention to spite. I don't think she believed him.
 

This is a little weird. If you choose split, you are taking a risk. If you choose steal, you take NO risk, because if the other person has steal you've lost it anyway.

Do you go there to win the game or do you go there to show everyone how wonderful you are?

Humanitarian feelings aside, it seems to me you should always take the option with no risk.
 

Sonic: I don't have a "risk" either from playing my strategy, except the risk of not screwing over someone and taking half the money. I.e. my only 'regret' is when I get half the pot instead of all of it.

And if I happen to bump into someone playing my strategy, we both get money. If everyone thinks like you and does the "rational" thing, then no one ever wins any money.

I'm not saying anything profound here, but it seems you aren't seeing the wrinkle of (pseudo) prisoner's dilemmas.
 

Of course, one wonders if the rules prevent (I am sure they have to) verbal contracting such as, "I will give you half of what I win tonight if you do the same". Verbal contracts, with video for verification are enforceable, aren't they?
 

I guess I wouldn't trust anyone who goes on this show in the first place. I don't think it attracts more humanitarians than greedy people.

You can always split the money afterwards backstage. Nothing stopping that....
 

I was thinking that.

You just say "I'm going to steal and then I'm going to give you half. So do you either a) trust me and be happy with half or b) settle with getting nothing. Up to you" The downside of course is that this strategy is a little intimidating. Its likely to make the person steal because they think you're a bully and are happy with nothing nothing if it means you get nothing.

Also, does anyone else get the feeling they just witnessed the birth of a supervillain?
 

It's seems like we're missing some context. I got the distinct impression that the girl didn't trust the guy and his zealous promises not to betray may indicate she had good reason to be suspicious. Had he perhaps betrayed previously? If that's the case, she's a vengeful genius. She screwed a guy who probably deserved it and walked away with all the loot.
 

The Blackadder Says:

The assumption in a lot of the comments here is that the girl was putting on an act, and that what she really wanted was for the guy to vote share and her steal so she could keep all the money. I don't think that's right. I think that her ideal really was for them to split the money. It's just that while splitting was preferable to her stealing everything, her stealing everything and both stealing was preferable to the other guy stealing everything from her.

Basically, people don't want to be a jerk, but they really don't want to be a sucker.

Incidentally, when I first watched the clip, I was sure that the guy was going to steal the money from her. So while I was surprised, it wasn't quite as bad as I was fearing.
 

I threw away my plasma tv the minute I found out TLC was suing Jon Gosellin. Hasn't he returned the $180,000 to Kate? Why can't they find it in their heart to forgive him? Why be so heartless TLC? Please forgive him and take him back, Kate. TLC, why kill the goose that laid the golden egg?
 

"I bet that girl works for Exxon."

Why do you say that, Bob? Because she stabbed the climate "skeptics" and their partners in the coal-funded "astroturf" lobby by acknowledging cause for concern and advocating rebated carbon taxes ?

Or because enviros view Exxon`s "change of heart" as a sham designed to slow any carbon policy whatsoever?

BTW, I agree w/ Caveman and Blackadder here; it`s clear that the woman didn`t want to end up a sucker again.

That "sucker" term is precisely the one used by Elinor Ostrom in a recent talk in Sweden.chi
 

LOL Andy! Devastating!
 

Bob,

I'm actually of the opinion that a lot of the reason traditional game theory gets things wrong isn't because of a failure of rationality or because of a failure of equilibrium. I think it has to do with a failure to properly characterize payoffs - since payoffs are subjective.

So, for the girl, her payoff from playing "Steal" was either "100,000 pounds + feeling a bit guilty" or "0 pounds + feeling like you didn't get stabbed in the back" (depending on what the other guy did). Playing "Split" would be "50,000 + feeling honest" or "0 pounds + feeling like a gullible idiot". (Much like The Blackadder says.)

This also explains things like why my students almost never play the Ultimatem game "right".
 

Lucas, well said.

What we see is not simply a failure to properly characterize payoffs - since payoffs are subjective - but to actually understand what they are.

Silas Barta, in the post Bob linked to, noted that there are actually a number of unstated "games" involved in these games.