Just a few years ago, the idea of giving people money with no strings attached was seen as ludicrous in mainstream policy circles. This week, a documentary on so-called "guaranteed income" programs premiered at the Tribeca Film Festival that underscores just how much currency the idea has gained.

The film, "It's Basic," follows participants in guaranteed, or basic, income pilot programs across the U.S., highlighting the transformative impact a regular payday can have for Americans struggling to make ends meet. 

Produced by Michael Tubbs, the former mayor of Stockton, California, and founder of Mayors for a Guaranteed Income, the film aims both to further normalize such policies as way of supporting people in need, boosting local communities, and ameliorating many of the social and economic ills that afflict America. 

More than 100 cities across the U.S. are currently piloting basic income programs. The film follows five basic income recipients in different cities, its director, Marc Levin told CBS News.

Tubbs, who was the first U.S. mayor to launch a basic income program in 2018, said sentiment has already shifted in the years since he started doling out $500, no-strings-attached cash stipends to some residents. More recently, the startling rise in the cost of food, housing and other necessities of daily life has made the need for creating an income floor for many Americans all the more urgent, he said.

"I joke with all my mayor and county official friends on how they have it easy in many respects now that people are saying that yes...we need a guaranteed income in our community," Tubbs said. "So now we have mayors and county officials using public dollars, using COVID money, using taxpayer dollars."

Levin highlighted some of the positive effects basic income can have on recipients. He said one of the film's main characters, a single mother and school bus driver, likened having cash in hand to fueling her car. "Put a little gas in my tank and I'll show you how far I can go," she said in the film. 

"$500 is not that much money, but it can make a world of difference in people's lives," Levin told CBS News. "Especially people who are trying to move forward, who want to see a better life for their children, who want to help people."

Notably, the basic income recipients shown in the film are employed in fields including nursing, social work or transportation, but don't earn enough to stay above water.

"They're essential workers. They're doing jobs we need, they're helping other people, but they can barely make it by," Levin said. 

"We're seeing what can happen"

Tubbs said he's encouraged by the sheer number of programs that have sprouted up across the U.S., while he continues to push for basic income to become national policy. 

"For example, we saw with the child tax credit, a nationwide experiment with guaranteed income, that child poverty fell by 40%, but we didn't renew that policy," Tubbs said. "A big part of the work by this film and a big part of the work of Mayors for a Guaranteed Income is we're seeing what can happen."

Pilot guaranteed income program participants across the U.S. used their stipends to pay off credit card debt, get their cars fixed and buy clothing for their children. Rather than discouraging recipients from working, such initiatives often help people get higher-paying jobs or transition from part-time to full-time work, advocates of the programs say.

Research also shows guaranteed income improves recipients' physical and psychological health by reducing stress and anxiety. As Tubbs put it, "they're not suffocated by economic insecurity." 

Tubbs added: "So I'm excited about what would happen if it was actually a permanent policy and people had longer amounts of time to respond to market pressures, to invest in themselves, to go to job training and all the things we know that we've seen repeatedly over this country that people do when they're given this little bit of money and real opportunity."