The Comedy of the Commons
A lesson for the world from the goatherds of Herakleia
Note: This is one ‘from the archive’; it was my first post on this website, almost a year ago, at a time when my entire readership consisted of a few people and a goat.
It is the hereditary right of all Greeks to freely lecture others on ancient history - a right I will exercise in this post.
This week I became the happy owner of a book by the classicist and historian John Ma entitled Polis: A New History of the Ancient Greek City-State from the Early Iron Age to the End of Antiquity (2024). Aside from its own intrinsic merits, the book can be used to make a case for stronger interaction between the more scholarly side of the humanities (history, literary studies, etc) and the social sciences (in which I include economics). I say this because within about five pages of the opening chapter Ma tells a story that economists interested in the problem of the 'tragedy of the commons' should probably know.
The 'tragedy of the commons' is a phrase principally associated with two people - the microbiologist turned social theorist Garret Hardin, and the 2009 Nobel Laureate in Economics Elinor Ostrom. Hardin posed the problem and gave it its name. An impeccably precise definition is given by Vincent Ostrom (Elinor's husband) in a 1973 article:
Individualistic decision making applied to common-property resources will inexorably result in tragedy unless the structure of decision-making arrangements can be modified to enable persons to act jointly in relation to those resources as a common property. Potential recourse to coercive measures will also be necessary to preclude a hold-out strategy and regulate patterns of use among all users. Unrestricted individualistic decision-making in relation to common-property resources or public goods will lead to the competitive dynamic of a negative-sum game: the greater the individual effort, the worse off people become.
V Ostrom, 'Can Federalism Make a Difference?' In Publius, Vol. 3, No. 2, The Federal Polity (Autumn, 1973), pp. 197-237
Hardin presented the canonical form of the 'tragedy of the commons' in his 1968 essay where he introduced the parable of the herders:
Picture a pasture open to all. It is to be expected that each herdsman will try to keep as many cattle as possible on the commons. . . . 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. 1) 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. 2) The negative component is a function of the additional overgrazing created by one more animal. Since, however, the effects of overgrazing are shared by all the herdsmen, 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; 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.
G Hardin, “The Tragedy of the Commons." in Science 162 (1968), pp. 1243–48.
This has attained the status of a classic in the genre of philosophical gedankenexperiments, along with Hobbes' State of Nature and Rawls' Original Position. And as with Hobbes and Rawls, one of the criticisms levelled at Hardin is that his parable of the herders has little bearing on reality. The fact that this story about an imagined community facing a public-resource crisis was used to propose what he himself calls a 'fundamental extension of morality' (in this case, population control) has also contributed to making his article a perpetual source of controversy. Ostrom won her Nobel prize in part for her theoretical and empirical critique of Hardin's position. On the theoretical side Ostrom (& Ostrom) showed that Hardin's toy model was highly sensitive to small changes in assumptions so that - as Ostrom puts it - models reflecting a 'more eclectic (and classic) view of human behaviour' produced radically different outcomes from Hardin's original. Ostrom also conducted extensive fieldwork on governance arrangements associated with the management of common resources that makes the story of the herders appear less empirically relevant and so less generalisable than Hardin would suppose (see this great retrospective by Frischmann, Marciano, and Ramello, for more).
Well it turns out that Hardin's parable may be more 'natural experiment' than 'gedankenexperiment'. This is where Ma's new book comes in, which opens with a series of examples of how ancient Hellenic communities conceived of the 'Polis' (city-state). The first of these examples concerns the political community on the small Cycladic island of Herakleia, located just south of Naxos. What we know about this ancient community is largely the work of two French historians, Jules Delamarre and Louis Robert. In the 1890s Delamarre was exploring the neighbouring island of Amorgos when he happened upon a fragmentary inscription that had been transported from Herakleia. Datable to the third century BCE the text concerns a momentous decision by the people of Herakleia (Herakleitoes) to collectively disengage from the pasturing of goats:
I swear by […] and Herakle and the other [gods] who hold sway over the island, and if I keep my oath, may it turn out [well] for me, and if I break my oath may it turn to the opposite. If someone, in trying to forcibly introduce goats or to raise them, in contravention of this decree and the oath, should kill some men among those who try to prevent it, let the relatives of the victim and the whole commonwealth of the island prosecute him; as for whatever expense is incurred for the judgment, let everyone contribute his share; and let the hieropoios inscribe this decree on the stone stele and set it up in the shrine of the Mother of the Gods; let the expense of the stele and the inscription come out of the public treasury. These matters are to be considered as concerning the protection and safety of all the Herakleitoes and of the inhabitants [of the island].
J Ma, Polis: A New History of the Ancient Greek City-State from the early Iron Age to the End of Antiquity, Princeton University Press (2024), p.4
As with most archaeological reconstructions we have to make conjectures under incomplete information. It is a fragment of a larger text that has disappeared and is presumably unrecoverable. Ma likens it to an 'isolated comet' in the historical record. However the evidence we do have points to the hypothesis that the third century Herakleiotes were acting to contain the risk of ecological collapse and eventual desertification. Put another way, they were facing what Hardin, in a separate paper, called 'competitive exclusion'. Two populations (goats and men) with differential growth rates occupying a shared ecological niche competing until resource constraints bite and drive one population to migrate or collapse. We can conclude this for three reasons: (1) A brief survey of the resources of the island, particularly the supply of water and cultivatable land indicate that the stability of its ecological carrying capacity was a matter of extremely fragile equilibrium; (2) as modern Greeks on islands like Samothraki have learnt, the goat problem has not gone away and is not easily ameliorated, even with modern technology; (3) At the time Louis Robert came to Herakleia, the fate that the islanders of the third century so feared had come to pass - it was no longer the site of a thriving political community but, as Ma evocatively puts it, 'like the island of the cyclops', a pasture for goats. Today, Herakleia is included among the 'erimonisia' islands (the deserted ones).
On its surface, the case of Herakleia would appear to confirm Hardin's thesis insofar as it shows a community having to invoke emergency measures to rescue a depletable public resource. But everything about the language in the fragment which records the Herakleiotes response to the crisis suggests that Hardin's description of the herders utility functions is wrong. Indeed, the most interesting thing about the case of Herakleia is that this decree is framed as a matter of collective-action, as opposed to pure coercion, which is ultimately where Hardin's argument carries you (even if he does not want to admit it). Ma's analysis is very interesting:
'The decision mobilised common institutional resources - deliberative, judicial, financial, but also ideological. Its measures were formally declared necessary for the community's safety (phulake kai soteria), a legal category protecting it against amendment or reversal, but also an invocation of the public good. The document, transcribing the whole transaction of the meeting in its institutional setting (including the motion as proposed, and almost certainly procedural details such as the proposers of the motion and presiding bodies at the meeting), was inscribed in permanent form and displayed in sacred space, the shrine of the Mother of the Gods, as a record and as monument of the political community in action'
J Ma, Polis: A New History of the Ancient Greek City-State from the early Iron Age to the End of Antiquity, Princeton University Press (2024), p.4
Hardin's model excludes by its own internal gearing an outcome like that on Herakleia, where the agents could form a 'political community with the collective capacities to decide its own fate'. In the high political language of the lapidary decree found by Delamarre there is no sense of men 'locked into a system of compulsion'; the opposite is true. Hardin says in his 1968 paper that the only solution to the tragedy of the commons is 'mutual coercion mutually agreed upon', which to me sounds roughly right (even if Ostrom disagrees), but he never explains how such agreement can be found on the basis of the way he had forced his wretched herders to weigh their own utilities. The solution, in the Hardin world, comes by way of deus ex machina rather than rational political action, which his model does not allow.
Ma goes on to ask, 'what should we call this political community' found on Herakleia, with its ability to self-regulate via deliberative assembly, and uses this as a springboard for his nuanced study of the 'poetics of community' in ancient Greece. He is a careful writer and in this book, which is his magnum opus, is a model of scholarly restraint. I, on the other hand, am only interested in clicks and views - so I will offer some speculations by way of conclusion.
Ecological disasters and Malthusian traps are problems we now face on a global scale. If the mathematician Misha Gromov is to be believed Malthus is arguably more relevant than ever before. The Herakleiotes response to impending catastrophe was to use the entirety of what Ma calls their 'common institutional resources'. Those resources are the difference between the imaginary outcome of Hardin's parable and that on Herakleia, enshrined as Ma says in the hard stone of its sacred architecture. They are the stuff missing from the model. If Ma's analysis is correct they are also the characteristic resources of a relatively special type of social unit - the Polis - albeit in one its primitive forms. What are the common institutional resources of a global community that is so massive that the activity on Herakleia would not even register as statistical noise? And if those 'institutional resources' are insufficient for the crises that menace the horizon, how should we improve them?
Further, the bit of the Herakleia fragment that cannot be translated into the language of Hardin-style utilities - 'koinon' which Ma glosses as 'things owned by the polis but also the polis itself' - points toward a concept that has an unhappy history in economic thought in the 20th century - the common good. Hardin does not mention the common good but will allow himself to invoke the Benthamite criterion of the 'greatest good for the greatest number' which, I hardly need add, is not necessarily the same thing. I would recommend that, almost a quarter of the way through the 21st century, finding a suitable formulation of the common good and restoring the use of such language in political discourse should be at the top of the agenda. But be warned, this may require what Warren McCulloch once called a journey through the 'den of the metaphysicians'.