I am reminded of a game we played in elementary school:
There are 100 pieces of candy in a jar, and 20 students. Each student gets to vote “share” or “selfish”. If EVERYONE votes to share, the candy is split evenly. If ONE person votes “selfish”, they get all the candy. If MORE than one person votes “selfish”, no one gets candy, and the experiment is repeated until either the candy is distributed, or X iterations (3-5 seems normal) have passed.
Before each iteration, the students are allowed to discuss strategy. The solution, of course, is for a single trustworthy person to make a binding commitment to vote “selfish” and then evenly distribute the candy. By pre-commiting to vote “selfish”, everyone else knows that voting “selfish” themselves will result in no candy—unlike a commitment to have everybody share.
I’ve always considered it a decent test of group rationality and social skills whether or not this consensus actually gets reached before the final iteration. I’ve seen groups that hit on this, had a single iteration with a few outliers testing it just to be sure that the person would really vote “selfish” like they said, and then implementing the strategy. I’ve seen others where 10-20% of the audience simply would not believe the person who made the pre-commitment, and so there was never a successful iteration
Yes, but this being a school setting, “I made a promise to the teacher” is usually considered sufficiently binding. For a more advanced level of rationality, I’d say that coming up with a plausibly binding commitment strategy would be part of the challenge :)
Anyone can ruin it deliberately, true—it works best with a cooperative group, not a competitive one. Modifying it for a competitive group would definitely remove it from the real of “useful introductory ideas”, but would probably still be a useful exercise for more advanced classes.
Candy is also concrete and engaging—most people don’t respond as enthusiastically to raffle tickets or $0.25. As part of a larger set of challenges, using play money with some sort of modest exchange of play money → small prizes at the end of the session might work.
Doesn’t need to be candy, necessarily. Money’s the first thing that comes to mind, but if that’s prohibitively costly to maintain while keeping the prizes attractive, you could play with probabilities: build a set of diverse prizes of approximately equal value, say, and instead of money or candy distribute tickets to a raffle where the winner’d be able to choose one prize. That might have some funny consequences in this experiment, though, depending on the quirks of how people think about probabilities.
I am reminded of a game we played in elementary school:
There are 100 pieces of candy in a jar, and 20 students. Each student gets to vote “share” or “selfish”. If EVERYONE votes to share, the candy is split evenly. If ONE person votes “selfish”, they get all the candy. If MORE than one person votes “selfish”, no one gets candy, and the experiment is repeated until either the candy is distributed, or X iterations (3-5 seems normal) have passed.
Before each iteration, the students are allowed to discuss strategy. The solution, of course, is for a single trustworthy person to make a binding commitment to vote “selfish” and then evenly distribute the candy. By pre-commiting to vote “selfish”, everyone else knows that voting “selfish” themselves will result in no candy—unlike a commitment to have everybody share.
I’ve always considered it a decent test of group rationality and social skills whether or not this consensus actually gets reached before the final iteration. I’ve seen groups that hit on this, had a single iteration with a few outliers testing it just to be sure that the person would really vote “selfish” like they said, and then implementing the strategy. I’ve seen others where 10-20% of the audience simply would not believe the person who made the pre-commitment, and so there was never a successful iteration
This all hinges on trusting the supposedly trustworthy person, of course.
Yes, but this being a school setting, “I made a promise to the teacher” is usually considered sufficiently binding. For a more advanced level of rationality, I’d say that coming up with a plausibly binding commitment strategy would be part of the challenge :)
Doesn’t that rely on everyone eating candy? One person who doesn’t eat candy and therefore isn’t invested in the outcome could wreck that.
Also: theoretically, a student could win hundreds of pieces of candy? I’m sure the parents were very happy about that.
Anyone can ruin it deliberately, true—it works best with a cooperative group, not a competitive one. Modifying it for a competitive group would definitely remove it from the real of “useful introductory ideas”, but would probably still be a useful exercise for more advanced classes.
Candy is also concrete and engaging—most people don’t respond as enthusiastically to raffle tickets or $0.25. As part of a larger set of challenges, using play money with some sort of modest exchange of play money → small prizes at the end of the session might work.
Doesn’t need to be candy, necessarily. Money’s the first thing that comes to mind, but if that’s prohibitively costly to maintain while keeping the prizes attractive, you could play with probabilities: build a set of diverse prizes of approximately equal value, say, and instead of money or candy distribute tickets to a raffle where the winner’d be able to choose one prize. That might have some funny consequences in this experiment, though, depending on the quirks of how people think about probabilities.