Stockton, California, is distributing $500 monthly stipends to the city's poorest families as part of a basic-income trial.

The city just released results from the past eight months of that program: Most participants spent the money on food and clothing.

Critics of basic income suggest that cash stipends reduce the incentive for people to find jobs.

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When Mayor Michael Tubbs of Stockton, California, suggested giving residents in his city $500 a month with no strings attached, he wasn't floating a new idea. The system of paying someone for being alive — now known as universal basic income — stretches back to the 16th century. Tubbs got the idea from Martin Luther King Jr., who proposed a guaranteed minimum income for citizens in 1967.

Today, it's still considered a radical approach. The system's critics say it reduces the incentive for people to find jobs and uses up government funds that could be better spent elsewhere.

But the idea has gained a national platform in part thanks to the 2020 Democratic presidential candidate Andrew Yang, who has promised to deliver payments of $1,000 a month, or $12,000 a year, to all US citizens over 18.

Tubbs' program, which started in February, could serve as a test case. For eight months, 125 Stockton residents living at or below the median income line (about $46,000 annually) have been getting $500 monthly stipends. The money is distributed through the mail in the form of debit cards.

This week, the city released the first set of data about the program. Most participants, it found, had been using their stipends to buy groceries and pay their bills.

Stockton's basic-income recipients spent the most money on food

On average, participants in Stockton's trial spent a plurality of their stipends (about 40%) on food and another 24% on sales and merchandise, including trips to Walmart or dollar stores. Another 11% went to paying their utilities, and about 9% went to buying gas and repairing their cars.

That left about 16% to be divided among categories like medical expenses, transportation, education, insurance, recreation, and self-care.

Residents in Stockton. AP Photo/Gosia Wozniacka, File

One resident, 48-year-old Zhona Everett, told the Associated Press that after paying her bills, she used the rest of the stipend to pay off her wedding ring and donate to her church. She also had enough money to go on a date with her husband, who works with her at a Tesla factory about 60 miles from Stockton.

"I was very excited to see it already working and making a difference in so many people's lives," Tubbs told Business Insider in April. "I'm now much more resolute in this idea that, if it's not a panacea ... it should be considered as one of the many solutions to ensure that people have an economic floor."

The data indicates that about 43% of the program's participants have a full- or part-time job. Some are disabled and others stay home to care for children or an elderly parent. Only 2% are unemployed and not actively seeking work.

The program is designed to last for 18 months, so it still has about 10 months to go.

'Every time you do something new, it's scary'

Finland and the Spanish city of Barcelona have also both launched basic-income trials, and Sweden has set aside about $325,000 for a pilot experiment as well.

Tubbs' effort is the first major basic-income program led by a US city. In 2012, his city became the largest in the nation at the time to declare bankruptcy. Today, about a quarter of Stockton's population lives below the federal poverty line.

Tubbs at the TED 2019 conference in Vancouver, British Columbia. Bret Hartman/TED

"I came into doing the pilot without a fully formed perspective — or as fully formed as it is now — but really more out of curiosity," Tubbs said in April. "If this was a solution that could work, I wanted to test it out."

Read more: A mayor is giving his city's poorest residents $500 a month, but he thinks there are still obstacles to rolling out basic income in the US

When he took office in 2016, Tubbs was just 26 years old, making him one of the youngest mayors in US history. He's now 29 and a soon-to-be father — something he said made the mission of his basic-income trial feel even more urgent.

"Childcare costs are real," Tubbs said. "We're now looking at how are we going to save up to have somebody help us watch our child. It definitely has made me that much more passionate and that much more impatient with the status quo."

Tubbs said he was never too concerned about whether his basic-income idea would be controversial.

"My team was more nervous than I was," he said. "I honestly will tell you this, I didn't really see much risk."

But he did find himself explaining his idea to many constituents one-on-one, he added.

"Every time you do something new, it's scary," Tubbs said. "You have to convince people that, 'No, it's going to be OK. We're going to be safe. And we'll all be better off for it.'"

Correction: This article has been updated to reflect that Stockton in 2012 was the largest US city to declare bankruptcy, not the first.