1.2 Tragedy of the commons
At about the same time as the Limits to Growth was published, Garret Hardin published a parable called The Tragedy of the Commons (Hardin, 1968). Hardin was an economist and his exposition was aimed at economists. One of the main tenets of free market economics, first formulated by Adam Smith in 1770, is that economic wellbeing is maximised when all the participants in the market pursue their own self interest. This famous principle had been used to justify many excesses by those with wealth and power, nevertheless its fundamental veracity was not questioned and the sustained economic growth of the capitalist economies was attributed to the operation of this principle.
Hardin’s story concerns an area of common land on which a group of villagers are able to graze their cattle. Like any area of grazing land the commons will have a limited carrying capacity, that is the ability to provide food for animals on a sustainable basis. If the number of cattle on the common exceeds its carrying capacity then the animals will not have as much food as they could eat, with the result that the yield of meat or milk will be slightly reduced. Figure 5 illustrates the concept of carrying capacity and the decline in yield as more animals are introduced onto the land.
For simplicity assume that there are fifteen villagers each with one animal on the common land. Each animal produces a yield of 30 units. One villager decides to put a second animal on the common. Because the number of animals now exceeds the carrying capacity of the land the yield per animal will be slightly reduced, to say 28 units. However the villager who introduces the second animal is clearly better off because he now has two animals producing meat or milk rather than one; his produce increases from 30 units to 2 x 28 = 56 units. The other villagers will, if they adopt Adam Smith’s dictum, now act in their own self-interest and also add a second animal each. By this point with 30 animals on the common the yield per animal has dropped to 12 units, so each villager now has a produce of 2 x 12 = 24 units, less than the initial yield of 30 units when they each owned a single animal. Worse still, if the villagers persist in adding animals to the common the land will become overgrazed and be unable to support any animals at all – the commons are destroyed.
The logic of this parable is inescapable and runs directly counter to the free market assumption that pursuing self-interest results in the best outcome. With this simple example Hardin was able to demonstrate that when a resource is limited market economics would not produce a sustainable outcome. It had long been recognised that there were many social reasons for governments to intervene in markets, for example to promote more equable distributions of wealth or to provide universal education facilities. What Hardin’s publication justified was a new style of intervention, the management of a limited resource so as to produce a sustainable outcome.
Unfortunately some interventions based on Hardin’s model have subsequently proved problematic because the situations were misidentified as commons situations by outsiders. The parable is often incorrectly used as a justification for privatisation of natural resources, e.g. fencing of communal land in Africa (particularly Botswana) and water privatisation in less-developed as well as industrial countries. The concept of carrying capacity is also not simple, nor fixed, but can vary with season and patterns of use.
It is always difficult to know whether publications such as Limits to Growth and The Tragedy of the Commons really shaped opinion or whether they were noticed precisely because there was a growing awareness of the issues of sustainability. There is an important contrast in scale between the two publications. Whereas Limits to Growth was concerned with the global economy and global limits, Hardin’s paper focused on a much smaller scale, an area of common land. It is not difficult to see that the types of arguments used in both cases apply at all scales, local, national, international and global. Together they provided a powerful counter-argument to the accepted wisdom, namely that economic growth through the operation of competitive free markets would provide solutions to all the problems of development, poverty, food supply and so on.
SAQ 2 Identifying ‘commons’
Which of the following do you consider should be treated as a ‘commons’ in Hardin’s sense of a limited shared resource? In each case you identify as a ‘commons’ state the limiting resource/factor involved.
- The Atlantic Ocean
- The River Thames
- The New Forest (an area of mixed woodland and pasture in the south of England)
- The air in Paris
- The oil and gas reservoirs in the North Sea
- A village green
- A nuclear power station.
The Atlantic Ocean
- Not an obvious commons because it is well connected with other water resources. Fish stocks within the Atlantic Ocean could be regarded as a commons, but not the ocean itself.
The River Thames
This is a commons in the sense of providing a source of fresh water to a large population.
The New Forest (an area of mixed woodland and pasture in the south of England)
A commons in that it is tourist area open to a wide range of visitors.
The air in Paris
Whilst the whole atmosphere can be regarded as a common resource, the particular air over a city is in constant motion and exchange with other air and as such is not, of itself, a commons resource. Where air becomes trapped, as in the Los Angeles basin, then there is a stronger case for regarding it as a commons.
The oil and gas reservoirs in the North Sea
These are a commons which it is widely accepted will be exploited and depleted within a finite time period.
A village green
Whilst conforming to the description of Hardin’s parable this is only to be regarded as a commons if the green is exploited or used in some way. If it is simply regarded as a useful amenity to look at then it is not useful to regard it as a commons since no amount of ‘looking’ will deteriorate the resource.
A nuclear power station
Not a commons in any sense.
Before leaving this subject it is important to point out that whilst this parable is a valid criticism of market economics as a means of managing finite common resources, it does not mean that all such resources have been or will be exhausted by over-use. In most communities, which rely upon a common resource, there are traditions of rules and practices that ensure that the common resource is not over-exploited. In a review of commons issues (Whose Common Future? Reclaiming the Commons, The Ecologist (eds.), 1993) there are many examples of such local regulation, ranging from water resources in the Philippines, forests in Finland, lobster harvesters in Maine, wild rice harvesting in Canada and grazing in Tanzania. This local control is a theme I will explore further in the next section. For the time being it is important to recognise that Hardin’s parable has often been incorrectly used as a justification for the imposition of external, centralised control on ‘common’ resources, a reflection of prevailing values and beliefs in many organisations and amongst many, but not all, professionals.