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'Snowdrift' game tops 'Prisoner's Dilemma' in explaining cooperation (2007)

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Re: 'Snowdrift' game tops 'Prisoner's Dilemma' in explaining cooperation (2007)

#61

Post by lisper »

quadrangle wrote: post #48
lisper wrote: post #28

Note that the SD is not actually a dilemma. The PD is a dilemma because you ALWAYS do better for yourself in any given iteration by defecting no matter what your opponent does. In the SD, if your opponent defects, you still do better for yourself by cooperating. So of course people will cooperate more under those circumstances. The only thing left to argue about is what the payoff matrix for real-world situations loo…

You're correct in most of your description, but it's STILL a dilemma. It's a game of chicken. The dilemma is wanting to wait to see what the other player decides, so the dilemma is everyone refusing to decide. https://en.wikipedia.org/wiki/Snowdrift_game (redirects to chicken game)

You're right. In fact, upon reflection, it is the PD which is not really a dilemma but rather a paradox. The logically correct move in PD (assuming a purely utilitarian quality metric) is always clear: if the game is non-iterated (or iterated with a known horizon) then defect. Otherwise play tit-for-tat. This is true no matter what your opponent does. In the SD the logically correct move depends on your prior on what your opponent is likely to do.

Re: 'Snowdrift' game tops 'Prisoner's Dilemma' in explaining cooperation (2007)

#62

Post by throwa_way_ »

whack wrote: post #54

TLDR: In Prisoner's Dilemma, defecting is a dominant strategy, and both players defecting is the only Nash equilibrium. In Snowdrift, there is no single dominant strategy, and no Nash Equilibrium exists at all. By design, the Snowdrift game rewards cooperation more than Prisoner's Dilemma, so it's no surprise that people cooperate more in Snowdrift. The real question is which game better models reality. http://www.ga…

You are wrong. There do exist Nash equilibria in the game [0].

[0]https://en.wikipedia.org/wiki/Chicken_(game)#Best_response_m...

Re: 'Snowdrift' game tops 'Prisoner's Dilemma' in explaining cooperation (2007)

#63

Post by pasiaj »

jzl wrote: post #55

I've seen a couple of oblique references to this in other comments, but I'll go a little deeper: if you want to truly understand the prisoner's dilemma scenario and how it relates to human, or more generally, animal behavior, there is incredible coverage of the topic in Richard Dawkins' The Selfish Gene. He pioneered the idea of running PD "competitions" in an attempt to discover the best evolutionary strategy for PD…

I thought Tit-for-tat was the strategy that always repeated opponents last move. "Tit-for that with forgiveness" was the strategy that would occasionally cooperate even after an opponents defection.

Re: 'Snowdrift' game tops 'Prisoner's Dilemma' in explaining cooperation (2007)

#64

Post by Danihan »

Practicality wrote: post #51
Danihan wrote: post #45

Earlier quoted context omitted.

It does, no one really has a net worth one way or another when they are a child. Define righteous? Define immoral? Capitalism rewards providing actual value to people. It doesn't reward shallow niceties and self-righteousness, those are common.

Capitalism sometimes rewards those who provide value, but more often than not has no problem rewarding people for spouting self-righteousness. If you think that everyone who gets rewarded in a capitalist society do so because they provide value then you have to ask: What value do scam artists provide?

Depends on the scam.

I don't know any rich scam artists. I do know hundreds of wealthy technology professionals, however.

Re: 'Snowdrift' game tops 'Prisoner's Dilemma' in explaining cooperation (2007)

#65

Post by majewsky »

Danihan wrote: post #45
majewsky wrote: post #40

Earlier quoted context omitted.

A good reputation score would start out at +/- 0 and not punish you for being the lone righteous guy in an otherwise immoral neighborhood.

It does, no one really has a net worth one way or another when they are a child. Define righteous? Define immoral? Capitalism rewards providing actual value to people. It doesn't reward shallow niceties and self-righteousness, those are common.

> Define righteous? Define immoral?

The point here was that credit scores do not only rate your own behavior, but also those of people around you. If your neighborhood is bad, your credit score might reflect that instead of your own performance as a debtor. And if your neighborhood becomes hip and gains a better reputation, your credit score might improve even though you're still the same person.

Re: 'Snowdrift' game tops 'Prisoner's Dilemma' in explaining cooperation (2007)

#66

Post by matt4077 »

AznHisoka wrote: post #16
Danihan wrote: post #3

The benefits of cooperation can't be modeled so simplistically, since the concepts of both long-term reputation and long-term retribution need to be taken into account.

Sometimes I wish life was just like that Black Mirror episode with reputation scores for everybody. Nobody wants to cooperate because there is hardly any long term reputation to worry about when interacting with most people (ie cutting off that car in the highway, being rude to that stranger next to you)

Society, and even biology, has invented all sorts of mechanism to reward/punish you for actions. The emotion of shame, for example, is a strong incentive to behave as expected, even among strangers. Shame (and pride) are probably evolutionary adaptions to make the connection between an action and the resulting change in your reputation more immediate.

On the other end of the scale, criminal law punishes you for large transgressions, and sometimes prizes reward you for good deeds (although the latter is mostly achieved via market mechanisms).

Both criminal law and awards also work via reputation, by publicising your actions to a wide audience.

It's also interesting to contrast the discussion in this threat to any number of HN threats on freedom of speech in the last weeks. There, the idea that someone's reputation could be tarnished by their participation in a neo-nazi torch parade was generally considered to be the end of freedom.

Re: 'Snowdrift' game tops 'Prisoner's Dilemma' in explaining cooperation (2007)

#67

Post by jamie_ca »

I came across an interactive applet last month (on Reddit maybe?) at http://ncase.me/trust/

It explores IPD with a few different strategies, and I found it quite interesting. I'd be curious to see how the various mechanics of it would work with ISD.

Re: 'Snowdrift' game tops 'Prisoner's Dilemma' in explaining cooperation (2007)

#68

Post by whack »

throwa_way_ wrote: post #62
whack wrote: post #54

TLDR: In Prisoner's Dilemma, defecting is a dominant strategy, and both players defecting is the only Nash equilibrium. In Snowdrift, there is no single dominant strategy, and no Nash Equilibrium exists at all. By design, the Snowdrift game rewards cooperation more than Prisoner's Dilemma, so it's no surprise that people cooperate more in Snowdrift. The real question is which game better models reality. http://www.ga…

You are wrong. There do exist Nash equilibria in the game [0]. [0] https://en.wikipedia.org/wiki/Chicken_(game)#Best_response_m...

You're right, my bad.

Re: 'Snowdrift' game tops 'Prisoner's Dilemma' in explaining cooperation (2007)

#69

Post by jzl »

pasiaj wrote: post #63
jzl wrote: post #55

I've seen a couple of oblique references to this in other comments, but I'll go a little deeper: if you want to truly understand the prisoner's dilemma scenario and how it relates to human, or more generally, animal behavior, there is incredible coverage of the topic in Richard Dawkins' The Selfish Gene. He pioneered the idea of running PD "competitions" in an attempt to discover the best evolutionary strategy for PD…

I thought Tit-for-tat was the strategy that always repeated opponents last move. "Tit-for that with forgiveness" was the strategy that would occasionally cooperate even after an opponents defection.

I copied those bullet points from the wikipedia article but yeah the wording is a little inexact. I think "quick to forgive" just means "retaliation only has a memory of one move".

Re: 'Snowdrift' game tops 'Prisoner's Dilemma' in explaining cooperation (2007)

#70

Post by arthurcolle »

PeachPlum wrote: post #44

See also https://www.sciencedaily.com/releases/2016/09/160915085719.h... Two people can hunt deer together, but if they are alone, they can only hunt rabbits. The person belonging to the Envious group will choose to hunt rabbits because he or she will be at least equal to the other hunter, or maybe even better; the Optimist will choose to hunt deer because that is the best option for both hunters; the Pessimist will…

I'm at the edge of my seat!
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