Being common is tragic, but the tragedy of the commons is still true

Changing fertility

In 1968, when Hardin published, is really when rich world birth rate started to fall off the cliff. One reason is that contraception became both cheap and effective, but that's actually a minor point.

The usual estimate is that its availability explains some 10 per cent of the change in actual fertility: the other 90 per cent is explained by changes in desired fertility.

That desired fertility changing because the world got richer: and some of the behaviour change being because people finally noted that it had. The name of the game of life being, of course, to have grandchildren. Achieve that and you've won.

Rising wealth meant that you only needed to have two or three children yourself to give that 99 per cent chance of having the little ones. Rather than needing 8 or 10 to manage that, as was true of most previous generations.

So, given that it was no longer necessary for women to be either pregnant or suckling all their fertile years they stopped doing that. And a richer society also raised the opportunity cost of being that permanent mother. For a richer society provides many other things that can be done and so raises the cost of doing any single one of them.

So Hardin was right about his general construction of the theory: but wrong in the field to which he applied it. One out of two ain't bad for intellectual propositions, so we'll applaud rather than blame him.

That Elinor Ostrom is the only woman ever to have got a share of an economics Nobel is true, that she worked with this problem of commons tragedies is also true. But what she found out is very much more interesting than refuting Hardin's basic contention, of showing that the Tragedy never happens.

For what she found, through her detailed empirical research, was that there's a third possibility as well as the private property, or government regulation solution. Which is that it is possible, at times and in places, for voluntary restraint to solve the problem.

People aren't stupid, they can often recognise this commons problem and then self-organise to do something about it. Villagers might, to use the example of grazing commons again, note that there's only a certain carrying capacity of said verdant grassy stuff and thus agree among themselves to limit how many animals they'll put on it.

That this is so should be obvious, given that we do in fact have nomadic pastoral societies that have managed to exist for thousands of years now. Something, given the absence of either private property or government over them, must have limited their predations upon those natural resources.

As Ostrom pointed out, it's that people aren't dumb and that voluntary cooperation does happen among humans. Which is what people then do: agree among themselves and voluntarily restrict access to those scarce resources, if this needs to happen.