Getting serious about affordable housing

When I was at the New Partners for Smart Growth conference in Kansas City, I saw a speaker argue that walkability increases property values (a proposition I'm not taking a position on, at least not in this blog post).   When someone asked about affordability, he suggested inclusionary zoning as a solution.

I am perfectly willing to stipulate for the sake of argument that inclusionary zoning may be an appropriate solution in a cheap city like Kansas City, where housing is affordable for most people most of the time, and only a few poorer people have great difficulty finding housing.  But in expensive cities like New York and San Francisco, affordability isn't just a problem for the poor; its a problem for the middle and upper middle class.  In such places, setting aside a few units for "affordable" housing is not going to prevent housing prices from affecting the region's quality of life.  Instead, we should seriously think about whether it is good for a city to have housing prices far exceeding incomes.