The mayor's proposal doesn't just violate the federal and state constitutions, which have nearly identical restrictions on takings. It would also make the city's shortages worse. Faced with the prospect of potential expropriation, many owners would likely withdraw properties from the market or not list them in the first place. New York's rent-stabilization laws have already induced owners to abandon thousands of apartments that can't be profitably maintained or upgraded. The mayor seeks to make city policy more severe by "freezing" rents for hundreds of thousands of units, preventing even the modest increases permitted under current law….

The mayor often decries the city's "systemic inequities" that have made living there more onerous. A great opportunity to make good on that rhetoric would be to target the real barriers to access: the exclusionary zoning rules that severely limit the amount and types of housing that can be built on most of the city's residential land….

Mamdani has rightly praised cities like Austin, Minneapolis and Auckland, New Zealand, which have seen the virtue in empowering private owners to build new housing. Such YIMBY — or "yes in my backyard" — zoning deregulation reliably increases supply and reduces prices. The "Block by Block" plan includes a few steps in this direction…. But the effect of such measures would be muted by expropriation and expanded rent control…..

The political right has its own snake-oil housing policies. Tariffs and mass deportation of immigrants make housing more expensive by increasing the price of building materials and the costs of construction, respectively….

But counterproductive right-wing policies don't justify Mamdani's. To alleviate the "deepening housing crisis," stop digging a hole with more government control of the kind that caused it in the first place.