> You mean through exclusionary rules, investing in monitoring and punishment etc all of which divert resources from the productive activity solely by the existence of the incentive to overuse the "commons" or others' goodwill.

No, I mean through collective policing and social pressure. In villages before privatizaton, free-riders faced social pressure, shame, and other consequences for violating the group trust. This is how most societies operated for the bulk of human history.

> True, while the subgame unique subgame perfect equilibrium of most models is full free-riding, most lab experiments show less than full free-riding. That does not mean the incentives are not there.

The lab experiments show "less than full free-riding" because humans are predominantly a social species, not a value-maximizing algorithm.

> That's a silly statement: No one decided to invent money in a similar process of invention like the lightbulb. Instead, coins, tokens, and other recognized mediums of exchange dominated over barter because barter is inconvenient and inefficient.

Except there's no historical record of that happening anywhere. The two things that look like money are trade goods between distant groups and coinage required by rulers for taxes or tribute. There's no record of money being invented de novo to replace barter in societies which didn't already have it.

> Even animals can learn to use a medium of exchange[1].

Obviously, but I haven't seen any record of chimps spontaneously deciding to coin money, so I'm not sure what the point here is.

Edit for the point I missed:

> Why are dorm bathrooms not as clean as bathrooms in your house?

Because my mother doesn't live in the dorm.