Hacker News Reader

Which cities, for example?

It is expensive in those other places for similar reasons as SF -- the government either tells them they can't (through zoning), or makes it very expensive (through regulation, like IZ / "affordable" housing), or limit profitability (rent control), or some combination of the above. All of these reduce the supply of new housing.

Generally the cities where housing is expensive are exactly the ones where the government is telling people they can't build (or making it very expensive to get approval). Do you have a specific example of a city such as you claim?