The Tragedy of the Commons Author(S): Garrett Hardin Source: Science, New Series, Vol
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The Tragedy of the Commons Author(s): Garrett Hardin Source: Science, New Series, Vol. 162, No. 3859 (Dec. 13, 1968), pp. 1243-1248 Published by: American Association for the Advancement of Science Stable URL: http://www.jstor.org/stable/1724745 Accessed: 05/02/2009 12:11 Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use provides, in part, that unless you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use. Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at http://www.jstor.org/action/showPublisher?publisherCode=aaas. Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit organization founded in 1995 to build trusted digital archives for scholarship. We work with the scholarly community to preserve their work and the materials they rely upon, and to build a common research platform that promotes the discovery and use of these resources. For more information about JSTOR, please contact [email protected]. American Association for the Advancement of Science is collaborating with JSTOR to digitize, preserve and extend access to Science. http://www.jstor.org What Shall We Maximize? Population,as Malthus said, naturally tends to grow "geometrically,"or, as we would now say, exponentially. In a finite world this means that the per The of the Commons capita share of the world's goods must Tragedy steadily decrease. Is ours a finite world? A fair defense can be put forward for The population problem has no technical solution; the view that the world is infinite; or that we do not know that it is not. But, it requires a fundamental extension in morality. in terms of the practical problems that we must face in the next few genera- tions with the foreseeable it Garrett Hardin technology, is clear that we will greatly increase human misery if we do not, during the immediatefuture, assume that the world available to the terrestrial human pop- At the end of a thoughtful article on sional judgment . ." Whether they ulation is finite. "Space" is no escape the future of nuclear war, Wiesner and were right or not is not the concern of (2). York (1) concluded that: "Both sides in the present article. Rather, the concern A finite world can support only a the arms race are... confronted by the here is with the important concept of a finite population; therefore, population dilemma of steadily increasing military class of human problems which can be growth must eventually equal zero. (The power and steadily decreasing national called "no technical solution problems," case of perpetual wide fluctuations security. It is our considered profes- and, more specifically, with the identifi- above and below zero is a trivial variant sional judgment that this dilemma has cation and discussion of one of these. that need not be discussed.) When this no technical solution. If the great pow- It is easy to show that the class is not condition is met, what will be the situa- ers continue to look for solutions in a null class. Recall the game of tick- tion of mankind? Specifically, can Ben- the area of science and technology only, tack-toe. Consider the problem, "How tham's goal of "the greatest good for the result will be to worsen the situa- can I win. the game of tick-tack-toe?" the greatest number" be realized? tion." It is well known that I cannot, if I as- No-for two reasons, each sufficient I would like to focus your attention sume (in keeping with the conventions by itself. The first is a theoretical one. not on the subject of the article (na- of game theory) that my opponent un- It is not mathematically possible to tional security in a nuclear world) but derstands the game perfectly. Put an- maximize for two (or more) variables at on the kind of conclusion they reached, other way, there is no "technical solu- the same time. This was clearly stated namely that there is no technical solu- tion" to the problem. I can win only by von Neumann and Morgenstern (3), tion to the problem. An implicit and by giving a radical meaning to the word but the principle is implicit in the theory almost universal assumption of discus- "win." I can hit my opponent over the of partial differential equations, dating sions published in professional and head; or I can drug him; or I can falsify back at least to D'Alembert (1717- semipopular scientific journals is that the records. Every way in which I "win" 1783). the problem under discussion has a involves, in some sense, an abandon- The second reason springs directly technical solution. A technical solution ment of the game, as we intuitively un- from biological facts. To live, any may be defined as one that requires a derstand it. (I can also, of course, organism must have a source of energy change only in the techniques of the openly abandon the game-refuse to (for example, food). This energy is natural sciences, demanding little or play it. This is what most adults do.) utilized for two purposes: mere main- nothing in the way of change in human The class of "No technical solution tenance and work. For man, mainte- values or ideas of morality. problems" has members. My thesis is nance of life requires about 1600 kilo- In our day (though not in earlier that the "population problem," as con- calories a day ("maintenancecalories"). times) technical solutions are always ventionally conceived, is a member of Anything that he does over and above welcome. Because of previous failures this class. How it is conventionallycon- merely staying alive will be defined as in prophecy, it takes courage to assert ceived needs some comment. It is fair work, and is supported by "work cal- that a desired technical solution is not to say that most people who anguish ories" which he takes in. Work calories possible. Wiesner and York exhibited over the population problem are trying are used not only for what we call work this courage; publishing in a science to find a way to avoid the evils of over- in common speech; they are also re- journal, they insisted that the solution population without relinquishingany of quired for all forms of enjoyment, from to the problem was not to be found in the privileges they now enjoy. They swimming and automobile racing to the natural sciences. They cautiously think that farming the seas or develop- playing music and writing poetry. If qualified their statement with the ing new strains of wheat will solve the our goal is to maximize population it is phrase, "It is our considered profes- problem-technologically. I try to show obvious what we must do: We must here that the solution they seek cannot make the work calories per person ap- The author is professor of biology, University be found. The can- of California, Santa Barbara. This article is population problem proach as close to zero as possible. No based on a presidential address presented before not be solved in a technical way, any gourmet meals, no vacations, no sports, the meeting of the Pacific Division of the Ameri- can Association for the Advancement of Science more than can the problem of winning no music, no literature, no art. I at Utah State University, Logan, 25 June 1968. the game of tick-tack-toe. think that everyone will grant, without 13 DECEMBER 1968 1243 argument or proof, that maximizing time, a growth rate of zero. Any people volve unhappines. For it is only by population does not maximize goods. that has intuitively identified its opti- them that the futility of escape can be Bentham's goal is impossible. mum point will soon reach it, after made evident in the drama." In reaching this conclusion I have which its growth rate becomes an re- The tragedyof the commons develops made the usual assumption that it is mains zero. inthis way. Picturo a pasture open to the acquisition of energy that is the Of course, a positive growth rate all It is to be expected that each herds- problem. The appearance of atomic might be taken as evidence that a pop- an will try to keep as many cattle as energy has led some to question this ulation is below its optimum. However, possible on the commons. Such an ar- assumption. However, given an infinite by any reasonable standards, the most rangement may work reasonably satis- source of energy, population growth rapidly growing populations on art factorily for centuries because tribal still produces an inescapable problem. today are (in general) the most misera- wars, poaching, and disease keep the The problem of the acquisition of en- ble. This association (which need not be numbers of both man and beast well ergy is replaced by the problem of its invariable)casts doubt on the optimistic below the carryingcapacity of the land. dissipation,as J. H. Fremlin has so wit- assumptionthat the positive growth rate Finally, however, comes the day of tily shown (4). The arithmetic signs in of a population is evidence that t has reckoning, that is, the day when the the analysis are, as it were, reversed; yet to reach its optimum.