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The Tragedy of the Commons vs. The Three Musketeers

[Yossarian:] "We won't lose. We've got more men, more money, and more material. There are ten million men in uniform who could replace me. Some people are getting killed and a lot more are making money and having fun. Let somebody else get killed."
[Major Major:] "But suppose everybody on our side felt that way?"
[Yossarian:] "Then I'd certainly be a damned fool to feel any other way. Wouldn’t I?"
-- Catch-22

“In fact, four men such as they were - four men devoted to one another, from their purses to their lives; four men always supporting one another, never yielding, executing singly or together the resolutions formed in common; four arms threatening the four cardinal points, or turning toward a single point - must inevitably, either subterraneously, in open day, by mining, in the trench, by cunning, or by force, open themselves a way toward the object they wished to attain, however well it might be defended, or however distant it may seem. The only thing that astonished D'Artagnan was that his friends had never thought of this.?
-- The Three Musketeers

I suggest that the key words in these contrasting views of cooperation are “ten million? and “four.? One person in ten million deserting won’t change the course of a war, but if one swordsman in a group of four consistently puts his own safety ahead of the success of the group, the group is more likely to lose a fight, with severe consequences for everyone in the group.

Even without any mechanism to enforce cooperation, members of small groups may see that it is in their own interest to do what is necessary for their group to succeed. Larger groups, on the other hand, may need more powerful mechanisms to prevent members from putting individual interests ahead of collective (e.g., national) interests.

In 1974, Levin and Kilmer (Evolution vol. 28 p. 527-545) came to similar conclusions about the power of natural selection, acting on groups (a school of fish, say), to favor cooperation within groups. In order for group selection for cooperation to overcome individual selection for selfishness, they showed that group sizes “of less than 25 and usually closer to 10 were required?; their computer models also showed that “migration could not be too much greater than five percent per generation.? In other words, if even a small percentage of selfish individuals can switch to another group when their selfishness has undermined their current group, then differences in the success of groups have little effect on the evolution of individual traits that affect group success.


I just discovered your blog, and I'll be checking regularly as this particular problem is rather interesting to me.

A thought occured to me while reading this. Could social programs be considered a form of commons? That is, are police, fire, roads, and other government provided community services a form of commons? Could the apparent reluctance to establish other government services (like universal health care) be a reflection of fear of the failure of the commons?

I'm not sure I would accept the truth of that idea without evidence. Every previous analysis I've seen about what is called 'commons' deals with renewable natural resources being depleted through overuse. I'll have to consider it. Yet, I thought I'd share the thought.


People may argue about terminology (commons vs. public goods, etc.), but I agree that some of the issues are similar. Would people try harder to quit smoking if they couldn't count on government-supported health care (at least for the elderly)? Maybe, although negative personal savings rates in the US suggest that we don't think very far ahead. (See also the entry on "pork.") I remember seeing something in the Wall Street Journal, of all places, comparing total health care spending (public and private) in the US and Canada. Canadians got more health-care for less money, partly because the US spends so much money essentially fighting over who has to pay for it.

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