The example I learned involved cutting across the grass as a shortcut instead of walking on a path. No one person can damage the grass, but if everyone walks across the grass, it dies, reducing everyone’s utility more than gained by the shortcut.
For a real world example, I suspect that one’s intuition about the acceptability of copyright piracy depends on one’s intuitions about committing to pay for content and the amount of content that would exist.
In other words, it seems intuitive that the truly rational would voluntarily co-operate to avoid tragedies of the commons. But voluntary commitment to a course of action is hard to formally justify.
In general, there are situations where act utilitarianism says a choice is permissible, but rule utilitarianism says the choice is not permissible.
The example I learned involved cutting across the grass as a shortcut instead of walking on a path. No one person can damage the grass, but if everyone walks across the grass, it dies, reducing everyone’s utility more than gained by the shortcut.
For a real world example, I suspect that one’s intuition about the acceptability of copyright piracy depends on one’s intuitions about committing to pay for content and the amount of content that would exist.
In other words, it seems intuitive that the truly rational would voluntarily co-operate to avoid tragedies of the commons. But voluntary commitment to a course of action is hard to formally justify.
If everyone walks across the grass instead of on the path, that is strong evidence that the path is in the wrong place.
It does not follow from this that it would be good for everyone to cut across the grass.