Is it really as simple as building more housing?

[Sirius_]

No, another solution is to move institutions from highly dense areas and thus relax population overflow in those areas, at least in Europe. Only Germany has a properly decentralised country where the capital doesn't dominate in this respect. The UN being in NYC for example ain't exactly ideal. Move them to Gary, Indiana or some sh**t hole that needs it.

You can't seriously argue that the US isn't a decentralised country. NYC isn't even the capital.