system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: The Tragedy of the Commons

Is it just the concept of self-interest trumping the common good? Or is there more to it than that?
gpt
Imagine there's a pasture full of grass that's not owned by a private individual.  Farmers from around the area bring their cattle to this pasture to graze for free.  The act of grazing slowly destroys the pasture.  All farmers realize that if the pasture gets over-grazed that all of the grass will die and the pasture will be of no benefit to anyone.  If one farmer takes his cattle away from the pasture to let the grass regrow, another farmer will just take his place and the pasture will get destroyed anyway.  So what happens is that none of the farmers remove their cattle because the destruction of the pasture is seen as inevitable.

One proposed solution to this problem is to allow private ownership of the land.  The private owner can charge a small fee to each farmer who comes to the pasture.  When the pasture needs to recover, the private owner will only let a few (or no) farmers in, because if the pasture is destroyed then the private owner won't be able to make money off of it anymore.