Berlin has a massive shortage. Vacancy rates are at about 1.5%. Functioning housing markets are at about 3%.

It's wrong to suggest that vacancy rates are are necessarily sign of housing dysfunction.

Areas that are attractive to live always have low vacancy rates, because there's a reason that people want to live there.

The assumption that 'as many people ought to be able to live in a neighbourhood as should want to live there' - implied by the 'vacancy rate' issue just means 'every attractive area turns into Hong Kong'.

While there can be very good reason for more building as well - socialized housing is almost never the answer to that. It has a role in some situations, but generally not on the aggregate like that.

Usually this will have to do with permits, regulation - and frankly workers. Nobody wants to do the kind of labour necessary to build homes, and it's extremely hard to find workers to do that kind of work, which to anyone paying the least bit of attention should be a pretty big paradox.

'City overflowing with people who want homes to live don't want to make homes in which to live'

Probably there's a lot of bureaucracy to clean out and that's a good place to start.