The way we think
about environmental concerns was heavily influenced by Garrett Hardin's seminal
1968 essay on "The Tragedy of the Commons." In this essay, Hardin described the fate of a common pasture, unowned
and available to all. As Hardin
explained, in such a situation it is in each herder's self-interest to maximize
his use of the commons at the expense of the community at large. Each herder captures all of the benefit from
adding one more animal to his herd. Yet
the costs of overgrazing the pasture are distributed among every user of the
pasture. And when all of the herders
respond to these incentives, the pasture is overgrazed -- hence the tragedy. As Hardin explained it, the pursuit of
self-interest in an open-access commons leads to ruin. Without controls on
access and use of the underlying resource, the tragedy of the commons is
inevitable.
Hardin's essay is
tremendously important, not so much because he discovered the commons problem --
others had documented this dynamic before -- but because he popularized a useful
way of thinking about many environmental problems. As Hardin explained, the metaphor of the
commons can be applied to virtually any environmental resource. Instead of a pasture we could talk of a herd
of animals, a fishery, a lake or even an airshed. In each case, the underlying economic dynamic
is the same, and if access and use are not limited in some fashion, over-use is
inevitable as demand grows. [A quick
caveat: What Hardin called the "commons," is more properly described as an open-access commons, as there are some
resources that are owned or managed in common that do not suffer the tragedy
because they are subject to community management of some form or other, but the
central point stands.]
Hardin's diagnosis
is often identified as a rationale for prescriptive regulation Hardin famously
termed "mutual coercion, mutually agreed upon." This was his way of describing those regulations we adopt to keep a
common resource of any sort from befalling the fate of an open-access commons, and it's largely the path we've followed in environmental policy for the past fifty years.
Administrative regulations have produced some
gains, but also many failings. Our air
and water are cleaner today than forty years ago -- and substantially so -- but
many ecological resources are as threatened now as they ever were. Federal environmental regulation was not the savior many think, and many environmental regulations actually get in the way of further progress. The imposition of land-use controls under the Endangered Species Act, for example, discourages effective conservation on private land.
One thing that
Hardin overlooked is that the political process often replicates the same
economic dynamic that encourages the tragedy of the commons -- a dynamic
fostered by the ability to capture concentrated benefits while dispersing the
costs. Like the herder who has an
incentive to put out yet one more animal to graze, each interest group has
every incentive to seek special benefits through the political process, while
dispersing the costs of providing those benefits to the public at large. Just as no herder has adequate incentive to
withhold from grazing one more animal, no interest group has adequate incentive
to forego its turn to obtain concentrated benefits at public expense. No interest group has adequate incentive to
put the interests of the whole ahead of the interests of the few. The logic of collective action discourages
investments in sound public policy just as it discourages investments in sound
ecological stewardship. This, in addition to the pervasiveness of special-interest rent seeking, explains
many of the failings of centralized regulation. So despite the
environmental gains of the past half-century, real challenges remain, and the
tragedy of the commons is still with us.