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Why I give my students a ‘tragedy of the commons’ extra credit challenge

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Re: Why I give my students a ‘tragedy of the commons’ extra credit challenge

#61

I'm surprised no rich student ever just offered ahead of the tally that they'd pay everyone $x if no one choose 6, where x is more valuable than 4 points. He now has the ability to safely choose 6, and everyone else is paid for their cooperation.

Great, except votes are anonymous.

Re: Why I give my students a ‘tragedy of the commons’ extra credit challenge

#62

Actually, I think in this case the only rational choice is to ask for the 6 points. One of two things will happen: 1) Less than 10% will follow suit, in which case you'll get a 6 point boost, and you'll have secured an advantage over 90% of your classmates. 2) More than 10% will follow suit, and noone will get anything, in which case you will have no advantage over your classmates, and neither will any classmate have…

> Because the "points" have no intrinsic value except in comparison to your classmates This is where your logic is wrong. The professor is not saying the class is graded on a relative scale (for example, top 10% of the class gets As). If everyone gets two points, and it bumps up everyone's GPAs, then of course it will benefit them all, especially in comparison to people who are not in the class.

Yes, it's true that it sort of benefits everyone in the class vs people who did not take the class, but some classes are easy A's and some aren't, and everyone knows that. If the class becomes a slightly easier A because we all picked 2 points, then the effect will be relatively small. It would be a better experiment if he was handing out cash, even small amounts of cash.

Re: Why I give my students a ‘tragedy of the commons’ extra credit challenge

#63
post #38

Actually, I think in this case the only rational choice is to ask for the 6 points. One of two things will happen: 1) Less than 10% will follow suit, in which case you'll get a 6 point boost, and you'll have secured an advantage over 90% of your classmates. 2) More than 10% will follow suit, and noone will get anything, in which case you will have no advantage over your classmates, and neither will any classmate have…

> "points" have no intrinsic value except in comparison to your classmates this would be true if the course was graded on a curve, but the article makes clear that > the course grades are not curved.

Doesn't matter if there's a curve. Your grades are still only meaningful compared to your classmates. (ok, assuming you're not in danger of actually failing the class)

Re: Why I give my students a ‘tragedy of the commons’ extra credit challenge

#64

Actually, I think in this case the only rational choice is to ask for the 6 points. One of two things will happen: 1) Less than 10% will follow suit, in which case you'll get a 6 point boost, and you'll have secured an advantage over 90% of your classmates. 2) More than 10% will follow suit, and noone will get anything, in which case you will have no advantage over your classmates, and neither will any classmate have…

A lot of people are commenting on how the article said there would be no curve, but I interpreted your statement to mean a deeper comparison to other students: the intrinsic value of doing better or worse than them, that translates to actual physical results: better chance at valedictorian than them, better chance to stand out to the teacher, higher overall GPA, etc.

Exactly. Curve or no curve it doesn't matter.

Re: Why I give my students a ‘tragedy of the commons’ extra credit challenge

#66
post #61

I'm surprised no rich student ever just offered ahead of the tally that they'd pay everyone $x if no one choose 6, where x is more valuable than 4 points. He now has the ability to safely choose 6, and everyone else is paid for their cooperation.

Great, except votes are anonymous.

It doesn't matter because the requirement is NO ONE choose it. There is nothing to gain by selecting 6. The second you are writing 6 down on your paper, you better hope the 4 extra points are worth more to you than $x because you have absolutely invalidated the game, not "maybe" invalidated it.

If x is big enough to trivialize 4 points, I am pretty sure no one would choose it (or at least fell well below 10%). For example, if Richy Rich was in your class and offered $1million to EVERYONE as long as NO ONE chose 2, I am quite certain that even the most selfish actors would not write down 6. If he offered 50 cents than I'm pretty sure some people would. Binary search and you'll know how much a point costs.

(apologies if you commented before my edit)

Re: Why I give my students a ‘tragedy of the commons’ extra credit challenge

#67

The professor omitted the sole interesting number: what percentage of students choose 6 points. Is it typically 15% or is it typically 80%? It makes a huge difference. Most likely, it's a percentage low enough to indicate that the 10% threshold is carefully chosen. Otherwise he'd tell us. This is evidence that he has an agenda to promote (that people are too selfish), and that the facts don't support his agenda (most…

Or maybe it's 70% of the students who pick 6. Or 99%. Or maybe 10.01%.

The point is we don't know and can only speculate, just like the students in the experiment who don't have the signal either. It kind of sounds like you want to believe the professor has a bias, and are trying to speculate evidence to support that belief. Even in the article he talks about how picking 6 in the first round isn't viewed as selfish, just that this experiment demonstrates tragedy of the commons.

Re: Why I give my students a ‘tragedy of the commons’ extra credit challenge

#68

Actually, I think in this case the only rational choice is to ask for the 6 points. One of two things will happen: 1) Less than 10% will follow suit, in which case you'll get a 6 point boost, and you'll have secured an advantage over 90% of your classmates. 2) More than 10% will follow suit, and noone will get anything, in which case you will have no advantage over your classmates, and neither will any classmate have…

A lot of people are commenting on how the article said there would be no curve, but I interpreted your statement to mean a deeper comparison to other students: the intrinsic value of doing better or worse than them, that translates to actual physical results: better chance at valedictorian than them, better chance to stand out to the teacher, higher overall GPA, etc.

"better chance to stand out to the teacher"

On reflection, this might make me stop and think about it. It's supposedly anonymous, but it can't be anonymous to the professor, can it, or how would the points be awarded? This professor believes he's simulating the tragedy of the commons, so to act rationally and take the 6 points might cast you in a negative light in his eyes, which might not be worth the 6 points after all.

Re: Why I give my students a ‘tragedy of the commons’ extra credit challenge

#69
Its funny because we see the tragedy of the commons "fail" (succeed?) all the time in national elections: people are so afraid to "selfishly" choose the candidate they actually want to win (and thus cause the opponent to win) that we all "cooperate" on a sort-of ok choice (just like cooperating on 2 vs 6). I guess that's argument for penalties.

Re: Why I give my students a ‘tragedy of the commons’ extra credit challenge

#70

The professor omitted the sole interesting number: what percentage of students choose 6 points. Is it typically 15% or is it typically 80%? It makes a huge difference. Most likely, it's a percentage low enough to indicate that the 10% threshold is carefully chosen. Otherwise he'd tell us. This is evidence that he has an agenda to promote (that people are too selfish), and that the facts don't support his agenda (most…

I'm actually not convinced that making it a higher percentage threshold doesn't make cooperation less likely

at 10% (depending on class size) each student realizes that their noncooperation goes a good distance of the way towards that 10%

at say 50% threshold, each student thinks their noncooperation matters less, and thus is even less likely to cooperate

at least that's what I'd hypothesize, I suspect there is an interesting paper somewhere that explores this very phenomenon

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