Companies have long sought to obscure the details of their sick leave policies, but The Times has obtained new data from The Shift Project, a nationwide survey of tens of thousands of retail workers conducted by the sociologists Daniel Schneider of the University of California, Berkeley; and Kristen Harknett of the University of California, San Francisco. While the federal government reports aggregate data on benefits, the Shift Project data — from its most recent surveys in 2018 and 2019 — provides a look at the benefits offered by individual corporations, published here for the first time. This makes it possible to name names.

The vast majority of workers at large restaurant chains report they do not get paid sick leave, except in the minority of states and cities where it is required by law. The list of malefactors includes the giants of fast food, like McDonald’s, Subway and Chick-fil-A, as well as sit-down restaurants like Cracker Barrel, Outback Steakhouse and the Cheesecake Factory.

And it’s not just restaurants. The data also shows most workers at the supermarket chains Wegmans, Kroger, Meijer and Giant Eagle reported that they did not get paid sick leave. So did workers at retailers including American Eagle, Victoria’s Secret and the Gap.

Some major retailers, though, like Costco, Home Depot and the supermarket chain Aldi, have long offered paid sick leave as a standard benefit. Since the coronavirus arrived in the United States, however, only one major retailer, Darden Restaurants, which owns chains including Olive Garden and Longhorn Steakhouse and employs 170,000 hourly workers, has taken the lesson and announced that it will henceforth provide paid sick leave on a permanent basis.

After an employee at a Canton, Georgia, Waffle House tested positive for the coronavirus, the company said it would continue to pay the employee and quarantined co-workers. But a spokeswoman, Njeri Boss, said the company would not commit to offering similar benefits to other workers affected by the coronavirus. The company declined to comment on its existing paid sick leave policy, but 99 percent of surveyed Waffle House workers said that they don’t get paid sick days. Asked whether customers might reasonably be concerned about eating at a restaurant that refuses to pay sick workers to stay at home, Ms. Boss said the company expected sick workers to stay at home. And would Waffle House commit to paying workers for acting responsibly? “That’s a matter between us and our associates,” she said.

Importantly, large numbers of workers at companies that offer paid sick leave reported that they did not get paid sick leave. At Chipotle, for example, workers are eligible to take up to three paid sick days beginning the day they are hired, but 20 percent of surveyed Chipotle workers said they could not take paid sick days. Walmart, by far the nation’s largest private employer, extended paid sick leave to all employees in February 2019, but only 73 percent of the Walmart workers surveyed since then said that they could take paid sick days.

Mr. Schneider and Ms. Harknett said that workers often are unaware of sick leave policies, or feel unable to take advantage of them. Managers exercise considerable power over scheduling and hours, and the researchers said that workers, in interviews, often expressed concern about the consequences of requesting a sick day. Chipotle conceded in 2017 that a norovirus outbreak centered on a Chipotle in Sterling, Va., was caused by a sick employee who should have been sent home. New York sued Chipotle last year for violating worker protections, including the city’s sick leave law, at five locations in Brooklyn. In February, New York fined Chipotle for firing a worker who took three sick days. “It’s not enough to have an official policy,” Ms. Harknett said. “It has to be a policy that people feel they can use.”