What causes housing in the US to be too expensive?

New York

THE US has two big housing affordability problems. They're related - and solving the first would go some way towards solving the second. But they're not the same, and it's important to understand that.

The first problem is that some coastal metropolitan areas in the US are generating lots of good jobs but aren't building enough housing to keep up with employment growth. The main barrier to housing construction in these places is local regulation - zoning ordinances, environmental requirements, even affordable-housing rules. This problem has been getting a lot of attention lately. I've written about it several times over the past year, and it's the subject of new pieces in the past few days from TheEconomist and TheNew York Times.