Ilya Somin has posted an interesting disucssion on the Washington Post website about the many ways in which zoning hurts the poor. He quotes from, and links to, a Mercatus Center report in which:

Economist Steven Horwitz points out that restrictive zoning laws impede social mobility by making it difficult or impossible for the working class and poor to establish home-based small businesses. 

Somin adds that:

This is just one of several ways in which restrictive zoning policies harm the poor. An even more significant one is the way in which restrictions on new development artificially inflate the price of housing in many cities, thereby pricing many of the poor and working class out of the market. Economists have been criticizing such policies for many years. It isn’t just libertarians and free market advocates like Horwitz and Edward Glaeser of Harvard. Leading left-wing economists and policy analysts, such as Paul Krugman and Matthew Yglesias, have decried restrictive zoning as well….

Unfortunately, the pleas of both left and right-wing analysts alike have largely fallen on deaf ears. Ironically, despite the harm they inflict on the poor and disadvantaged, the nation’s most liberal cities also tend to have the most restrictive zoning laws. Cynics might argue that this is because the residents of these areas are actually “limousine liberals” who only pretend to care about the poor, but in reality support whatever policies put more money in their own pockets. In my view, the main culprit is not malevolence on the part of liberal voters but political and economic ignorance. The problem is not that voters are indifferent to the plight of the poor, but that most of them simply don’t realize that restrictive zoning exacerbates it.