The house in which I grew up was built in 1913. It was part of a building boom in New York City’s outer boroughs fueled by the rising incomes, and rising aspirations, of erstwhile tenement-dwellers. As jam-packed Manhattan neighborhoods like the Lower East Side emptied out, once-bucolic stretches of Brooklyn, Queens and the Bronx were transformed with dizzying speed.

A century later, neighborhoods like the one I grew up in seem frozen in amber. The faces are different, to be sure, and so are the languages spoken by the locals. Crime has gone down and property values have gone up, and New York City is as desirable as it’s ever been. Yet we’ve had nothing like the building boom of the 1910s and 1920s that transformed the face of the city. Millions of low- and middle-income New Yorkers thus find themselves squeezed by skyrocketing rents, and hundreds of thousands of others who want to make their home in New York can’t afford to do so. 

In fairness, New York Mayor Michael Bloomberg has presided over the revitalization of the city’s waterfront, where new buildings really are sprouting up. Brooklyn’s Barclays Center will eventually be surrounded by new housing units, and an ambitious new mixed-use neighborhood is planned for Manhattan’s West Side.

But even when these various developments come to fruition, demand for housing in New York will continue to outstrip supply by a wide margin. The inevitable result of New York City’s failure to allow for more housing is gentrification and displacement. If you don’t build enough new housing in the most convenient and amenity-rich neighborhoods, affluent professionals will settle in adjacent neighborhoods, bidding up rents and driving people of more modest means out of their neighborhoods and in some cases out of the city. This means longer commutes and less access to economic opportunity for those who need it most.

One irony of New York City politics is that the most adamant opponents of gentrification tend to also be the most adamant opponents of development, the only force that can contain its spread. Recently, Dylan Matthews of the Washington Post surveyed the housing policies backed by New York’s leading Democratic and Republican mayoral candidates. All of them favor inclusionary zoning, in which developers are obligated to set aside a certain number of housing units for low- and middle-income households. These programs are a boon to those lucky enough to secure an affordable housing unit. But as Robert Ellickson first explained over 30 years ago, inclusionary zoning mandates effectively raise the cost of development, and in doing so, they tend to limit housing opportunities for low- and middle-income households overall. Worse still, inclusionary zoning mandates tend to be packaged with property tax abatements for developers that are eating away at the city’s tax base.