Series Info...Trials, Triumphs & Trivialities #206:

Strategic Insights: Three Community Issues

by Shannon Appelcline

Over the last three articles, I've discussed three issues which each balance community good versus individual greed: The Prisoner's Dilemma, The Tragedy of the Commons, and The Free Rider Problem.

I find these issues interesting because they come from three widely divergent fields of study: game design, societal study, and economic study. However, they all cover largely the same topic.

Thus, to finish up my discussion of these community issues, I'm going to compare and contrast them in a less structured and more freeform manner than the articles to date in these series.

Are They All the Same Thing?

Broadly, the three community issues that I've been talking about cover the same ground. Each one provides incentives for personal greed that do a longer-term community ill. I'm surprised that I haven't been able to find more articles comparing them, because they strike me as a very apt topic for interdisciplinary study.

However, I also think there are subtle differences between them.

The Tragedy of the Commons and the Free Rider Problem are the two most similar, but they're really flip sides of the same coin. In the Tragedy, individuals damage the community through intentional greed, while in the Problem they do so through willful neglect. One is action and the other is inaction, and that's the most fundamental way to differentiate the two.

The Prisoner's Dilemma is a bit farther afield, but I think that's because of its specificity. Much as in The Tragedy of the Commons, each Prisoner's Dilemma participant is given the option to willfully damage the community good in order to improve their personal lot. However, there are two elements that make the Dilemma distinct from the Tragedy.

First is the speed with which the damage occurs. In the Tragedy of the Commons (and for that matter, the Free Rider Problem), we're talking more about a gradual decline when people choose individual greed. However in the Prisoner's Dilemma, the levels of community damage are immediate and extreme. If one person defects, the community is immediately worse off and if two defect, both the community and the individuals end up considerably for the worst.

The second element that makes the Prisoner's Dilemma distinct is that it's so explicitly a two-player problem. If you have more than two players, the math of the Prisoner's Dilemma rapidly falls apart, because of those aforementioned abrupt levels of change.

In comparing all three of these community issues, I think that I'd say that The Tragedy of the Commons and The Free Rider Problem form the two extremes of a spectrum where individuals can do harm to a community through action or inaction. The Prisoner's Dilemma, meanwhile, is largely a special case of The Tragedy of the Commons, but one that highlights how you can use the general community issues to create real-life problems.

Making It Concrete

I've already talked quite a bit about how to make each of these issues concrete by offering strategy game and reality game examples. However I think by examining how The Prisoner's Dilemma specifies The Tragedy of the Commons you can get even more comfortable with laying out a real-life example of each of these problems.

Most obviously, you can do this by determining how much greed results in societal failure. The Prisoner's Dilemma became a two-player problem because it defined total failure as two defections. If you're laying out any of these problems you have to decide when the "tipping point" occurs. Is it when one person defects? Two? Fifty percent? Everyone?

Besides figuring out failure based on numbers of defection, you can also do it based upon damage done. While The Prisoner's Dilemma is entirely binary (based on whether you defect or not), The Tragedy of the Commons instead presumes cumulative damage. One sheep overgrazing for fifty years might do as much damage as fifty sheep overgrazing for one year. The Free Rider Problem offers a much more free-form look at total damage than either of these other possibilities, because any participant could give any level of support to the community.

Beyond this, you can also measure damage done based on whether the community is worse off or just some of the individuals. In The Tragedy of the Commons, for example, greed does overall community damage, but an individual makes up for it because his individual greed outweighs his percentage of the damage. This is taken to a further extreme in The Prisoner's Dilemma where the defecting prisoner takes no damage upon himself (except perhaps in reputation). Though things are theoretically worse for the community as a whole, that damage is entirely heaped upon the other prisoner if he didn't defect. You could imagine the other extreme where each individual does notable damage to himself when he hurts the community, but at the point the dilemma becomes less hard to solve. Most concrete examples of these issues will probably fall somewhere in between.

Finally, you could also mix and match many of the other details seen in these three community issues. Are decisions simultaneous? Are they blind? Is there an opportunity for iterative feedback? Is there the chance of altruistic punishment? Though some of these possibilities have only been used in some of these issues, they're all similar enough that there's a lot of possibility for the specifics to cross over from one to another.


That's it for me on The Prisoner's Dilemma, The Tragedy of the Commons, and The Free Rider Problem. As I've stated previously, this column is no longer publishing regularly, but I am planning to return to the topic of Collective Choice to write some articles on voting, in this American election year. I'll see you then!

[ <— #205: Strategic Insights: The Free Rider Problem | #207: Collective Choice: Ratings Inputs and Outputs —> ]

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