New York City—where takeout is a food group and ovens are for storing clothes—may soon get into the grocery business. If he wins the general election this November, Zohran Mamdani, the new Democratic nominee for mayor, has said he will build a network of municipally owned, affordable grocery stores, one in each of the city’s five boroughs. According to Mamdani, the city could help pay for the stores’ rent and operating costs by taxing the wealthy, and the stores won’t seek to turn a profit, enabling them to sell food at wholesale cost. In the vision Mamdani laid out in a campaign video, the stores’ mission would be combating “price gouging” by offering lower prices than corporate grocery stores.

If Mamdani is able to pull this off—a huge if, given the economic considerations, as critics are quick to point out—it will be the first time in American history that a city of New York’s size has commanded its own grocery stores. New Yorkers are in favor of the idea: Two-thirds of them, including 54 percent of Republicans, support public groceries, according to a March poll by the Climate and Community Institute, a progressive think tank. But because nothing exactly like Mamdani’s plan has ever been tried before in a large city, no one can be certain whether it will really be able to sell more affordable food, let alone help address food insecurity and health disparities in the city. What Mamdani has proposed is a $60 million experiment, with New Yorkers as test subjects.

A couple of other large American cities are trying out similar plans, but what little real precedent exists for Mamdani’s plan comes mostly from rural America. A handful of towns have opened municipally owned groceries, mostly because they had no choice: Small towns once relied on mom-and-pop shops, but these are vanishing as dollar stores proliferate and big-box retailers in larger rural cities monopolize the wholesale supply. Without a supermarket, residents have to either drive out of town for food or rely on convenience stores and dollar stores, which don’t stock many healthy options. In 2018, the town of Baldwin, Florida (current population 1,366), lost its only grocery when the local IGA closed. It became a food desert: The next-closest supermarket was 10 miles away—not a simple trip for older adults who don’t drive or for people without a car. The mayor proposed a municipally owned store, which opened the next year. In Kansas, the cities of St. Paul (population 603) and Erie (population 1,019) started their own grocery stores in 2008 and 2021, respectively. St. Paul had not had a supermarket since 1985.

The fates of these stores and their hometowns have varied. Baldwin Market became a lifeline for many residents, particularly during the pandemic. But it struggled to break even and closed in 2024. Now the town largely relies on a handful of convenience stores and a Dollar General as it awaits the rumored opening of a new private grocery. Erie Market similarly struggled to balance its books. Operations were a challenge; the store sometimes stocked expired food, and its refrigerated section lost power after a thunderstorm. Last year, the city leased it to a private owner, who has yet to reopen the store.

By contrast, St. Paul Supermarket has operated as a fully municipally owned grocery since 2013 (before that, it was funded by a community-development group) and shows no signs of closing. Its success has been attributed to community buy-in. Locals were motivated by the desire to preserve their city, fearing that the lack of a grocery store would drive away current residents and scare off potential new ones. “It’s a retention strategy, but it’s also a recruitment strategy,” Rial Carver, the program leader at Kansas State University’s Rural Grocery Initiative, told me.

The primary goal of a municipally owned store is to get food to people who need it. But the city will have to decide which food to stock and, inevitably, will face questions about how those choices influence the diet or health of potential customers. (Imagine the criticism a Mamdani administration might face for subsidizing Cheetos—or, for that matter, organic, gluten-free cheese puffs.) Theoretically, getting people better access to any sort of food can have health benefits, Craig Willingham, the managing director of CUNY’s Urban Food Policy Institute, told me. But so few examples of successful municipal grocery stores exist that there is virtually no research on their health effects.

Research on the health impact of opening a privately owned grocery in a food desert has had mixed results. An ongoing study of a food-desert neighborhood in Pittsburgh has found that after a supermarket opened, residents consumed fewer calories overall—less added sugar, but also fewer whole grains, fruits, and vegetables. A 2018 study set in a Bronx neighborhood with few grocery stores linked the opening of a new supermarket to residents eating more vegetables and fruit and consuming fewer soft drinks, salty snacks, and pastries, but their spending on unhealthy foods increased along with their purchases of healthy ones.

A new grocery alone won’t change food habits, according to a 2019 study led by Hunt Allcott, an economist at Stanford. “People shop at the new store, but they buy the same kinds of groceries they had been buying before,” Allcott told me. What does help nudge people toward buying healthier foods, he said, is making those foods affordable—while also taxing unhealthy items such as soda.

With so little background information to go on, there’s no telling how Mamdani’s experiment will play out in a big city—or whether it will even get off the ground. New York differs from the sites of other municipal-grocery experiments not only in its size and density but also in its general abundance of grocery stores. Proximity isn’t the major reason people can’t get food, healthy or otherwise, Allcott said—cost is. From 2013 to 2023, the amount of money New Yorkers spent on groceries rose nearly 66 percent—far higher than the national average. The city’s poverty rate—a metric based on the price of a minimal diet—is nearly twice that of the national average; from 2020 to 2023, one in three New Yorkers used food pantries. In Chelsea, a Manhattan neighborhood that is known for its luxury high-rises and is also home to a large housing project, some residents would rather take the train into New Jersey to buy groceries than shop at the expensive local supermarkets, Willingham said.

Grocery stores are tough business. Profit margins are as slim as 1 to 3 percent, and prices are largely determined by suppliers, who tend to privilege volume. A single grocer (or the small network that Mamdani envisions) won’t get as good a deal as a large chain. And running a store is hard, Carver told me: A manager needs to be nimble and adjust to customer demands, skills that municipal bodies are not exactly known for. In New York, at least, there’s reason to expect that public groceries wouldn’t actually be cheaper.

Mamdani (whose campaign did not respond to a request for comment) has acknowledged that New York’s city government might not be cut out for stocking shelves. If the pilot plan doesn’t work, he said on the podcast Plain English last week, he won’t try to scale it up. Yet he believes that it’s worth trying. “This is a proposal of reasonable policy experimentation,” he said.

National grocery costs are expected to increase 2.2 percent this year, according to the USDA. Price hikes will hit poor Americans even harder if Congress passes President Donald Trump’s megabill, which includes cuts to federal food-assistance programs such as SNAP. Among such threats to food affordability, the mere possibility of change could justify a trial of something new. Other large cities, too, are signing up as guinea pigs: Madison, Wisconsin, is in the process of opening a municipally owned store. Last year, Atlanta addressed food insecurity among public-school students and their families by opening a free grocery store—it functions like a food pantry but is stocked like a supermarket—funded by a public-private partnership. Its impact on health hasn’t yet been studied, but demand is high. “We do slots for appointments, and they’re immediately gone,” Chelsea Montgomery, the adviser to operations of Atlanta Public Schools, told me.

Mamdani’s proposal is hardly the first unorthodox policy experiment New York has considered. The city took a chance on congestion pricing to reduce traffic and fund public transit, on universal pre-K to guarantee access to early childhood education, and on supervised injection sites to curb the overdose crisis. All have achieved their objectives. Perhaps, in a decade, millions of New Yorkers will get their organic, gluten-free cheese puffs on the cheap at a city-owned market. Or perhaps the whole project will go the way of the city’s failed attempt to end poverty by offering cash in exchange for efforts to build healthy habits. The point of experimentation is to find out.