Far fewer than you'd think: The vast majority of Europe is in the same boat as the US.

Whenever there's value in agglomeration (ie, all the time), the value of well placed properties just skyrockets, because growth is only going to make that land better. That's why a common recommendation is to up the tax of land as to make speculation with valuable property a bad investment: It's already price like an auction, so higher taxes cannot increase rent prices. The problem is political, as countries with housing problems have a whole lot of individuals have a big percentage of their net worth in housing. Big tax increases would make their property values drop, and they'd be quite upset. So it solves the problem while losing elections.

Instead, governments are happy providing tax advantages to existing residents, in practice making prices go up even faster.