[ta2938489]

Borders are another way of saying "local control". If, all things being equal, you would rather that political decisions happen closer to you than further away, then you are in favor of (arbitrary) borders.

I think it's an error to view concepts such as "community" and "your country" as quaint abstractions while putting full faith in "the product" and "economic viability". Economic arguments are important, but not comprehensive to the human experience. All things being equal, I'd rather live in a decent place with a decent economy, than a terrible place with great economy, or the reverse.

So I am skeptical of arguments that demand economic optimality over all other competing concerns such as culture, "community", happiness, etc. Perhaps economic optimality has diminishing marginal returns?

[bharath28]

Economic optimality, in this case, is merely one of any number of quantifiable measures you can use to define what is decent vs terrible. How does the place of birth of people working jobs (that they are good at) change what you call decent or terrible - what is your measure?