Our self imposed scarcity of nice places
Everybody wants walkable cities, but nobody wants to live in tiny-ass flats.I'm a European and if you look at the size of housing here (perhaps excluding the few cities that have low population density) it's tiny in comparison to most of the USA (except for NYC).So as always there are pro's and con's - would you want to live in a city like NYC? Would you like to raise a family in those conditions?