Why can't meaningful competition happen at every level from between nations to between neighbors?
Sure, you can propose I merge my family with the family next door as a more "regionally-appropriate subdivision", but how can you justify it (or justify against it)?
It can make a lot of sense for different sections of the same metropolis to compete for residents, businesses, etc. The dynamics of which competition is healthy and constructive and which competition is unhealthy and destructive is an interesting problem, and it isn't settled by personal opinions of "common sense".
Oh, absolutely. I don't mean to suggest that that sort of local experimentation* isn't valuable: as you say, removing the ability for variation reduces policy to guesswork. It seems to me that that's more possible in a situation with a clearer idea of success (i.e. a stronger regional economy) than is possible with states that have competing priorities.
* In re-reading, I think my bias is to call that local variation experimentation rather than competition. I'm a technocrat at heart.
Sure, you can propose I merge my family with the family next door as a more "regionally-appropriate subdivision", but how can you justify it (or justify against it)?
It can make a lot of sense for different sections of the same metropolis to compete for residents, businesses, etc. The dynamics of which competition is healthy and constructive and which competition is unhealthy and destructive is an interesting problem, and it isn't settled by personal opinions of "common sense".