Reputations don't have to be "enforced," you may just be unable to access certain services without a certain number of other positive dealings with people trusted by a certain seller. For example, I may sell you a car part that you pay for upfront, but I may not sell you installation of said part unless you have a certain number of positive dealings with people within my social network. Reputation just follows you around like a credit score. A "social credit system" is a perfectly reasonable governance tool so long as it isn't centralized & you can't be black listed by some monopoly institution. There may very well be competing social credit syatems with different standards that people care about.
Discussion
You are correct. "Reputations don't require enforcement"
But the system that tracks and recognizes them does.
Enforcement from and by whom and how is certainly up for debate, but it will require enforcement nonetheless.
Not enforcement of reputation but of the rules and methods by which it is quantified and tracked.
Just need some sort of standard developed so that people can rate each other in different ways & those ratings can be weighted in some sane & helpful fashion. Lots of social graph problems to be solved in decentralized systems.
Which is why small communities are far more likely to accomplish and maintain a system that will work.
Any larger system will fail in the face of human nature.
Nah, I think, like Bitcoin & the internet in general we will see certain standards emerge that will spread & scale to facilitate the development of robust global trade networks