As a rational being, each herdsman seeks to maximize his gain. Explicitly or implicitly, more or less consciously, he asks, "What is the utility to me of adding one more animal to my herd?" This utility has one negative and one positive component:
- The positive component is a function of the increment of one animal. Since the herdsman receives all the proceeds from the sale of the additional animal, the positive utility is nearly +1.
- The negative component is a function of the additional overgrazing created by one more animal. Since, however, the effect of overgrazing is shared by all the herdsmen, while the negative utility for any particular decision-making herdsman is only a fraction of -1.
Adding together the component partial utilities, the rational herdsman concludes that the only sensible course for him to pursue is to add another animal to his herd. And another.... But this is the conclusion reached by each and every rational herdsman sharing a commons. Therein is the tragedy. Each man is locked into a system that compels him to increase his herd without limit—in a world that is limited. Ruin is the destination toward which all men rush, each pursuing his own best interest in a society that believes in the freedom of the commons. Freedom in a commons brings ruin to all (Hardin, 1968).
The lessons of the Tragedy of the Commons have been learnt many times over the millennia, but apparently have been forgotten as often. According to Hardin (1968), such tragedies have been repeated over the course of the human history. This is because human beings had suffered from a natural tendency of psychological denial as individuals continued to try to gain the maximum individual benefits at the cost to the society, whose sufferings extended to the individuals concerned. One of the solutions for Hardin is through education whereby such awareness and knowledge about the Tragedy of the Commons gets refreshed by generation after generation so that such wrong doings are to be avoided (Hardin, 1968). In conclusion, Hardin stresses that freedom in the commons brings ruin to all and the only solution is "mutual coercion, mutually agreed upon."(Hardin, 1968; 1992).
Interestingly (from a research point of view), for Hardin, the notion of the Tragedy of the Commons can be generalised and applied in a wide range of spheres in our life. Where he has suggested that such a notion may be used to enlighten a class of human problems which can be called "no technical solution problems"(Hardin, 1968). One member of this class of problems is the pollution problem. As Hardin puts it:
'In a reverse way, the Tragedy of the Commons reappears in problems of pollution. Here it is not a question of taking something out of the commons, but of putting something in—sewage, or chemical, radioactive, and heat wastes into water; noxious and dangerous fumes into the air; and distracting and unpleasant advertising signs into the line of sight. The calculations of utility are much the same as before. The rational man finds that his share of the cost of the wastes he discharges into the commons is less than the cost of purifying his wastes before releasing them. Since this is true for everyone, we are locked into a system of "fouling our own nest," so long as we behave only as independent, rational, free-enterprisers.'
The Tragedy of the Commons as a food basket is averted by private property, or something formally like it. But the air and waters surrounding us cannot readily be fenced, and so the Tragedy of the Commons as a cesspool must be prevented by different means, by coercive laws or taxing devices that make it cheaper for the polluter to treat his pollutants than to discharge them untreated. We have not progressed as far with the solution of this problem as we have with the first. Indeed, our particular concept of private property, which deters us from exhausting the positive resources of the earth, favours pollution. The owner of a factory on the bank of a stream—whose property extends to the middle of the stream—often has difficulty seeing why it is not his natural right to muddy the waters flowing past his door. The law, always behind the times, requires elaborate stitching and fitting to adapt it to this newly perceived aspect of the commons (Hardin, 1968). "
A selection from Dr. Jin's thesis. Complete document found at