As anyone who has visited New York in recent years can discern, the city is in the midst of an acute transit crisis, which has been greatly exacerbated by the feckless leadership of the notoriously small-minded governor of New York, Andrew Cuomo. Underinvestment and gross mismanagement have badly damaged the city’s subways, its lifeblood, and low-income commuters in the outer boroughs have been hardest hit. Money alone won’t solve all that ails the Metropolitan Transportation Authority, but the agency needs an infusion of funds to, among other things, modernize its dangerously antiquated control systems. The question is where the money will come from. Local commuters aren’t exactly thrilled by the prospect of paying higher fares, and local taxpayers are understandably reluctant to shovel more money into a transit agency notorious for its profligacy. Short of a federal bailout, which is nowhere on the horizon, New Yorkers will have to find someone willing to foot the bill.

And then there is displacement, fear of which looms large in the local imagination. As New York City has grown more desirable, it has experienced net population growth. While large numbers of New Yorkers leave the city every year, they are being replaced, and then some, by newcomers from elsewhere, including large numbers of high-skill professionals. Close to 9 percent of households in New York earn over $200,000, and it is no exaggeration to say that much of the rest of the city’s workforce caters to this slice of the population. This increase in high-end demand is, for most communities, the stuff of dreams, and it has redounded to the benefit of those fortunate enough to own property. However, New York City has failed to accommodate increased demand for housing by easing local land-use regulations that have, over the course of decades, drastically decreased the number of units that developers are allowed to build.

That artificially constricted supply has prompted affluent households to look beyond neighborhoods that have traditionally been the city’s most desirable, and that offer professionals the shortest commutes, to neighborhoods in Brooklyn and elsewhere that had hitherto been dominated by families of modest means. If established neighborhoods in the urban core had built more housing, it stands to reason that there would have been less spillover of the well-off to outlying neighborhoods. Gentrification can be a positive force, to be sure. For one, by reducing the concentration of poverty, it can improve the life chances of the poor children who remain in gentrifying neighborhoods, by reducing their isolation from society’s middle-class mainstream, a dynamic I touched on in National Review in 2014.

But these benefits do not extend to poor children who find themselves displaced from these neighborhoods, who might then settle in higher-poverty neighborhoods elsewhere in the city, or in less transit-rich inner suburbs. It is possible for gentrification to lower the concentration of poverty in a neighborhood without causing displacement, provided the supply of housing increases enough to accommodate increased demand, thus holding down rent increases. If the supply of housing does not grow sufficiently, however, displacement is a likely consequence.