Does America face an affordable housing crisis and, if so, why? This paper argues that in much of America the price of housing is quite close to the marginal, physical costs of new construction. The price of housing is significantly higher than construction costs only in a limited number of areas, such as California and some eastern cities. In those areas, we argue that high prices have little to do with conventional models with a free market for land. Instead, our evidence suggests that zoning and other land use controls, play the dominant role in making housing expensive.