Earlier quoted context omitted.
Those have to be really big cities, because in cities with reasonable public transport you can hop on a train or a bus from basically anywhere within city limits and reach the expensive center in less than half an hour.
>cities with reasonable public transport Does NYC qualify? I think you can still hit theoretical under-half hour times if you manage to get the subway right as your train comes in and don't have to walk too far from the stations to the doors. But if you live in New York the psychological barrier of dealing with that crap is big enough that people tend not to do it outside of commuting. It's a chore to get someone in…
> It's a chore to get someone in Brooklyn to come into the city to hang out unless it's right after work. And vice versa.
The issue, I think, is that young professionals have largely been priced out of Manhattan, and the East River acts as a psychological boundary. Even if it's just a short trip, you're still leaving/entering "the city".
As a side anecdote, the club Maxwell's in Hoboken closed a few years ago; the reason given was that most of the bands that played there were willing to cross one river to play a gig, but only a small fraction were willing to cross both, even though the trip wasn't substantially longer.