The tragedy of the commons is a theory that if lots of people have unlimited access to some shared resource, they’ll quickly use it all up and leave everybody worse off. It has been used as an argument for establishing (or increasing) property rights, privatisation, and government regulation.
The original idea came from a 1833 essay written by a man called William Foster Lloyd. Lloyd, like most economists of his time (and indeed, like many of ours now), saw all humans as fundamentally rational and utility-maximising. In other words, they made decisions based on what would benefit them the most. Lloyd pointed out that when lots of people are focused on improving only their own lot in life, the unintentional result could be negative consequences for everyone.
In 1968, the American ecologist Garrett Hardin expanded Lloyd’s theory and named it ‘the tragedy of the commons’. Hardin used the theory to justify his belief that the newish welfare state Western countries were then adopting was encouraging people to have more kids than society could look after.
Hardin’s criticism of welfare was that it basically functions as a government guarantee that nobody in a society will die because they don’t have the money to pay for necessities for food, shelter or medical care. That might sound oddly heartless, but Hardin was a Malthusian - someone who believes that at some point the human population would outpace food production, leading to an major shortage of food, many deaths and possibly the entire collapse of society into an apocalyptic fight for survival. He therefore saw unchecked population growth as a pathway to doomsday.
This worldview isn’t as bizarre as it may sound. The only reason we can currently make enough food to feed most of our seven-billion-strong population is that we’ve invented technologies which allow allowing us to produce more than has ever previously been possible. (And even then one in nine people don’t have enough food to lead a healthy active life.)
For Hardin, a world in which your kids would not survive if you had more than you could afford to keep had the advantage of stopping the human race from collectively overbreeding. He didn’t, however, push for the removal of all welfare from the needy. Instead, his solution to the tragedy of the commons was for governments to impose strict rules and regulations on how much of a resource people could use, including how many kids they could have.
Hardin’s work has been widely criticised and argued against since its publication. Most notably, the idea that a tragedy of the commons is inevitable (or even likely) when resources are commonly owned was rejected by work the Nobel-Prize-winning economist Elinor Ostrom carried out in the ‘90s and ‘00s.
Ostrom studied multiple real-life examples of what she called ‘common-pool resources’ and found that as long as some conditions - such as local decision-making power and an effective way to sort out arguments - were met, local groups were actually pretty good at preventing their overuse. Most people played fair, and individuals who tried to take more than their share were kept in line via tools like social shunning. Ostrom concluded that strict government regulation like Hardin called for was unnecessary and often counterproductive.