Panics about the supposed threat of socialism or communism are hardly new to American history, so the reaction in some quarters to the presumed victory of Zohran Mamdani, a self-described democratic socialist, in last week’s New York mayoral primary wasn’t surprising.“It’s officially hot commie summer,” the hedge-fund billionaire Dan Loeb wrote on X. A bit more shocking, perhaps, was the response of the Harvard economist Larry Summers, a former Treasury Secretary during the Clinton Administration, who accused Mamdani of advocating “Trotskyite economic policies,” which was presumably a reference to his calls for a rent freeze, free bus rides, government-run grocery stores, and higher taxes on millionaires and corporations. (Summers also said Mamdani had shown a great ability to learn during the campaign and expressed the hope that he would “provide much needed reassurance” to believers in the market economy.)

To be sure, these reactions to what might be called “Zohranomics” didn’t exactly stun Mamdani’s supporters, many of whom take criticisms from financiers and centrist Democrats as confirmation they are on the right track. Summers “never disappoints, does he?” Isabella M. Weber, a professor of economics at the University of Massachusetts, Amherst, who signed a public letter endorsing Mamdani’s campaign proposals, told me during a lengthy conversation last week. Weber rose to prominence during the COVID-19 pandemic, when she called for government price controls and published detailed research about how big companies were taking advantage of the global emergency to raise their prices and profit margins. Responding to Summers’s comments, she said that describing Mamdani’s program as Trotskyite was “absurd” and didn’t tell us anything “about what Mamdani’s agenda is trying to get at.”

In the open letter, which The Nation published a few days before the primary, more than two dozen progressive economists from the United States and other countries described Mamdani’s policy platform as “a bold yet practical blueprint to tackle some of New York City’s most urgent challenges—above all, the cost of living.” Weber told me that she felt Mamdani “did very well in presenting himself as someone who stands up for the affordability of life and focusses on what I have been calling ‘essentials’—the stuff that people can’t do without: housing, food, transportation, and child care. If you can’t afford that stuff, you are really pushed to the margins of society.”

Weber contrasted Mamdani’s proposals with the equivocations of Joe Biden’s Administration during the nationwide cost-of-living crisis that Donald Trump and other Republicans successfully exploited in last year’s election. She recounted how Biden, in his 2024 State of the Union speech, denounced corporations for capitalizing on a period of crisis by increasing their prices or reducing the size of their offerings, but then didn’t do much about it. After Kamala Harris replaced Biden on the Democratic ticket, she proposed a federal ban on price gouging by food suppliers and grocery stores. But she subsequently rowed back on the issue, Weber recalled, “based on pressure from similar quarters that have been criticizing Mamdani’s campaign.”

The critique of Harris’s proposal was that price controls don’t work, and the same charge is being hurled at Mamdani’s call for a rent freeze on roughly a million rent-stabilized apartments. (The freeze wouldn’t apply to the city’s million or so market-rate apartments.) In a controversial column that favored Andrew Cuomo over Mamdani but took aim at both, the New York Times’ editorial board said that a rent freeze “could restrict housing supply and make it harder for younger New Yorkers and new arrivals to afford housing.” The argument is that, if landlords and developers see a rent freeze, they would be deterred from investing in new affordable housing. When I put this point to Weber, she said that it was important to realize that Mamdani’s call for a rent freeze is accompanied by a pledge to build an additional two hundred thousand rent-stabilized units over the next ten years; his campaign plans to accomplish this by expanding public investments, changing zoning laws, and fast-tracking planning approvals. “If you only do a rent freeze without insuring that you also build, I don’t think that’s a great idea,” Weber said. “Given the severeness of the affordability crisis in New York City, the combination of a rent freeze and an aggressive build-out of affordable housing is a good idea.”

Creating more affordable housing is hardly a radical new mayoral goal, of course. In 2014, at the start of his eight-year tenure, Bill de Blasio also unveiled a plan to build or preserve two hundred thousand affordable apartments, and, in 2021, his administration announced that it had achieved this goal. Arguably, the most successful expansion of the city’s affordable-housing stock came with the construction of public-housing projects, which began during the Great Depression under Mayor Fiorello La Guardia, who established the New York City Housing Authority (NYCHA), and continued in the postwar decades. Subsequently, federal funding dried up, and public housing came to be associated with crime and other problems. In recent decades, New York’s mayors have built affordable housing primarily through public-private partnerships, in which for-profit and not-for-profit developers receive tax breaks and other forms of support for putting up buildings that are privately managed. Mamdani’s website says he will “recommit” to public housing, doubling the city’s investment in “major renovations of NYCHA housing” and using NYCHA-owned land, such as parking lots, as sites for more affordable housing—a proposal that de Blasio also championed.

That sounds sensible, and overdue, but the housing shortage facing the city is formidable: some recent studies say it needs to build as many as half a million new homes. Mamdani has put less emphasis on encouraging market-rate development. He has given a few nods to the “abundance” wing of the Democratic Party, such as pledging to eliminate parking minimums and encourage development around subway stations and other transport hubs. But the primary goal of his plan is to “unleash the public sector to build housing for the many.”

Another objective is to provide the city’s residents with cheap and healthy food. The Mamdani campaign says that its new grocery stores would operate in city-owned buildings in low-income areas that currently lack adequate options—so-called food deserts. It went on, “Without having to pay rent or property taxes, they will reduce overhead and pass on savings to shoppers.” Before moving to Massachusetts, Weber once lived in the Sunset Park neighborhood of Brooklyn, where she sometimes found it difficult to shop for healthy foods. “The price dimension”—of Mamdani’s proposal—“is important, but the other is the accessibility of nutritious food,” she said.

It’s important to note, as some media accounts haven’t, that Mamdani is proposing a pilot scheme of just five new stores—one in each borough. In a metropolis with more than fifteen thousand privately-owned supermarkets and grocery outlets, this seems like small beer. Nonetheless, Weber said that the experiment could be valuable. If it succeeded, it could be expanded, she noted, and ultimately it could encourage more competitive pricing in private stores: “If you have an alternative that is reliably cheap and doesn’t take advantage of opportunities to raise prices when they occur, that can change the pricing dynamic for whole sectors. That is potentially an important advantage that comes from having a public option.”

In many people’s minds, the term “public option” is associated with health care. But public transportation is a public option, too, and, as Weber pointed out, the proposal to make bus rides free fits in with Mamdani’s emphasis on basic needs. “Affordable transportation options are essential for your basic material well-being, to get to a job, make money, and earn a living,” she said. Some progressive thinkers and groups have extended the public option concept to other areas, including communications, financial services, and food retailing. In a recent article that cited Mamdani’s proposal on grocery stores, Becky Chao, the director of policy and research at the Economic Security Project, wrote, “Public options show what’s possible when governments respond to local communities’ needs and build real alternatives for their constituents, when we grapple with the imbalance of power in our economy, and focus on marketshaping solutions that constrain corporate power while building power for all Americans.” Of course, public options will only succeed if they deliver what they promise. For example, there’s no guarantee that city-run grocery stores would be able to provide cheaper and more nutritious foods. “That’s why you need a pilot,” Weber acknowledged. “To see if you can pull it off.”