Breaking the economist’s monopoly on the Tragedy of the Commons.


After taking attention away from economic rationality as a cause of overexploitation of common property, I introduce another more psychological mechanism, better suited to the mundane commons of everyday life. Mundane commons are important because they are one of the few instances of true self-governance in Western society, and thus one of the few training grounds for civic engagement. I argue that the “IAD” principles of the Ostrom Workshop, well-known criteria for self-governance of resource systems, don’t speak only to the very narrow Tragedy of the Commons, but to the more general problem of overexploitation.


The Tragedy of the Commons is the tragedy of good fudge at a crowded potluck. Individual guests each have an incentive to grab a little extra, and the sum of those extra helpings causes the fudge to run out before every guest got their share. For another mundane example, I’ve seen the same with tickets for free shows: I am more likely to request more tickets than I need if I expect the show to be packed.

The Tragedy has been dominated by economists, defined in terms of economic incentives. That is interesting because the Tragedy is just one mechanism for the very general phenomenon of overexploitation. In predatory animal species that are not capable of rational deliberation, population imbalances caused by cycles, introduced species, and overpopulation can cause their prey species to be overexploited. The same holds between infectious agents and their hosts: parasites or viruses may wipe out their hosts and leave themselves nowhere else to spread. These may literally be tragedies of commons, but they have nothing to do with the Tragedy as economists have defined it, and as researchers treat it. In low-cost, routine, or entirely non-economic domains, humans themselves are less likely to be driven by economic incentives. If overexploitation exists in these domains as well, then other mechanisms must be at work.

Economics represents the conceit that human social dynamics are driven by the rational agency that distinguishes us from animals. The Tragedy is a perfect example: Despite the abundance of mechanisms for overexploitation in simple animal populations, overexploitation in human populations is generally treated as the result of individually rational deliberation. But if we are also animals, why add this extra deliberative machinery to explain a behavior that we already have good models for?

I offer an alternative mechanism that may be responsible for engendering overexploitation of a resource in humans. It is rooted in a psychological bias. It may prove the more plausible mechanism in the case of low cost/low value “mundane” commons, where the incentives are too small for rational self-interest to distinguish itself from the noise of other preferences.

This line of thinking was motivated by many years of experience in shared living environments, which offer brownies at potlucks, potlucks generally, dishes in sinks, chores in shared houses, trash in shared yards, book clubs, and any instance where everyday people have disobeyed my culture’s imperative to distribute all resources under a system of private property. The imperative may be Western, or modern, or it may just be that systems of private property are the easiest for large central states to maintain. The defiance of the imperative maybe intentional, accidental, incidental, or as mundane as the resource being shared.

Mundane commons are important for political science, and political life, because they give citizens direct experience with self-governance. And theorists from Alexis de Toqueville to Vincent Ostrom argue that this is the kind of citizen education that democracies must provide if they aren’t going to fall to anarchy on the one side or powerful heads-of-state on the other. People cannot govern themselves without training in governance. I work in this direction because I believe that a culture of healthy mundane commons will foster healthy democratic states.

I don’t believe that the structural mechanisms of economics are those that drive mundane resource failure. This belief comes only from unstructured experience, introspection, and intuition. But those processes have suggested an alternative: the self-serving bias. Self-serving bias, interpreting information in a way that benefits us at the expense of others, is well-established in the decision-making literature.

How could self-serving cause overexploitation? Lets say that it is commonly known that different people have different standards for acceptable harvesting behavior. This is plausible in low-cost/ low-reward environments, where noise and the many weak and idiosyncratic social preferences of a social setting might drown out any effects of the highly-motivated goal-oriented profit-maximizing behavior that economists attend to. I know my own preference for the brownies, but I have uncertainty about the preferences of others for them. If, for every individual, self-serving bias is operating on that uncertainty about the preferences of others, then every person in the group may decide that they like brownies more than the other people, and that their extra serving is both fair and benign.

The result will be the overexploitation that results from the Tragedy of the Commons, and from the outside it maybe indistinguishable from the Tragedy, but the mechanism is completely different. It is an interesting mechanism because it is prosocial: no individual percieves that their actions were selfish or destructive. It predicts resource collapse even among agents who identify as cooperative.

The self-serving bias can help to answer a puzzle in the frameworks developed by the Ostrom Workshop. In their very well-known work, members of the Workshop identified eight principles that are commonly observed in robust common-property regimes. But only one of these, “graduated sanctions,” speaks directly to rational self-interest. The other principles invoke the importance of definitions, of conflict resolution, of democratic representation, and other political and social criteria.

Why are so many of the design principles irrelevant to rational self-interest, the consensus mechanism behind the Tragedy? Because it is not the only cause of overexploitation in self-governing resource distribution systems. The design principles are not merely a solution to the economist’s Tragedy of the Commons, but to the more general problem of overexploitation, with all of the many mechanisms that encourage it. If that is the case, then principles that don’t speak to the Tragedy may still speak to other mechanisms. For my purposes, the most relevant is Design Principle 1, in both of its parts:

1A User boundaries:
Clear boundaries between legitimate users and nonusers must be clearly defined.
1B Resource boundaries:
Clear boundaries are present that define a resource system and separate it from the larger biophysical environment.

By establishing norms, and the common knowledge of norms, this principle may prevent self-serving bias from promoting overexploitation. Norms provide a default preference to fill in for others when their actual preferences are unknown. By removing uncertainty about the preferences of others, the principle leaves participants no uncertainty to interpret in a self-serving manner.

Other psychological processes can cause overexploitation, but the design principles of the Ostrom Workshop are robust to this twist because they weren’t developed by theorizing, but by looking at real resource distribution systems. So even though they define themselves in terms of just one mechanism for overexploitation, they inadvertently guard against more than just that.