For centuries, the way people make money has stayed mostly the same: People earn a living based on the skills they bring to society. Doctors make more than plumbers because open-heart surgery saves more lives than fixing leaky toilets. Star athletes make more than teachers because entertainment is more lucrative than education.

But the recent evidence is overwhelming: Automated robots are replacing workers faster than our economy can handle. Some evidence even suggests that today's technology could feasibly replace 45% of jobs right now.

The consequence may ultimately be that people will no longer be able to make money based on their usefulness in society — because they won't be useful anymore. There has to be another system of income distribution, and the one that seems most poised to ease the burden is universal basic income.

Basic income is a form of income distribution in which people earn a monthly allowance to cover basic expenses like food, clothing, and shelter — whether they work or not. Over the last year, the idea has started spreading around the world. It's gone from Switzerland to the Netherlands to Finland to Canada, where programs could begin as early as next year.

The nexus of the American basic income movement is Silicon Valley, where techies are now realizing the importance of a fail-safe in the event that the leaps forward in automation they help create end up putting millions of people out of a job.

Albert Wenger, a partner at venture capital firm Union Square Ventures, for example, is currently at work on a pro-basic income book. And Jim Pugh, former analytics chief for President Obama, hosts regular weekend-long "Create-a-thons" in the Bay Area so artists and advocates can produce media centered around basic income.

A woman riding her bike in Utrecht. Michael Kooren/Reuters

"As the nature of work starts to change, disruption will certainly affect people's lives," Pugh tells Tech Insider. "But if you can guarantee that income floor to everyone, at least it won't drop people into desolate poverty."

The best estimates find that up to 50% of jobs risk automation by the late 2030s.

Certain jobs, like teachers, police officers, and business managers, are more immune to displacement given their human components. But the spectrum of jobs that are at risk is surprisingly vast. Surgeons may risk getting replaced by surgical robots just as easily as self-driving cars may replace long-haul truck drivers.

"It's not just the blue-collar area that seems at risk," Pugh says. "What we think is easy or hard does not correspond all that well to what's easy or hard for a computer."

Y Combinator, Silicon Valley's largest startup accelerator, seems to be leading the charge in the US in figuring out how to adjust to a robot takeover. Past startups incubated at Y Combinator include Dropbox, Zenefits, Reddit, and Airbnb, all of which are now worth billions.

Sam Altman, Y Combinator's president, wrote in January on the company blog that he believes in 50 years "it will seem ridiculous that we used fear of not being able to eat as a way to motivate people. I also think that it's impossible to truly have equality of opportunity without some version of guaranteed income."

Altman announced in that same blog post that Y Combinator was hiring a researcher to head a five-year experiment in which a select group of people will get monthly checks on top of their regular salary, no strings attached.

"My hope is that it'll inspire larger-scale experiments that governments might want to undertake, be it local, state, or federal government," says Y Combinator's Matt Krisiloff, who heads the company's fellowship program and will manage the basic income experiment.

But not everyone sees basic income as a solution to automation.

Ross Baird, executive director at Village Capital, a company that "finds, trains, and funds entrepreneurs solving global problems," sees basic income as a solution that arrives far too late to fix the problems society currently faces.

Baird doesn't believe robots will necessarily take over. He thinks it's arrogant that Silicon Valley wants to be the paternal figure that helps people in a robot-run dystopia, because smarter and more caring business practices can lead to a future without robots. Automation, he believes, is just what happens when businesses prioritize the bottom line over their workers.

"Assuming that machines will automate people's jobs and put people out of work is a way of thinking that treats most workers like commodities, rather than people who can contribute valuable things to companies beyond just X output," he says.

The way to reconcile that, Baird says, is for business owners to stop relying on low stock prices as a sign to lay off thousands of workers on a whim. Instead of using robots to cut costs, businesses could rely on creative, human-based solutions. They could invest in additional training, so people can branch out and perform more than one task.

Or, as Baird suggests, they could think about putting employees' prosperity ahead of the company's.

Pugh and Krisiloff believe strongly that robots' presence will grow in the future, but they also acknowledge basic income may not be the only solution.

Pugh, for instance, says a New Deal-type program, in which people are put to work repairing the existing infrastructure of bridges, buidings, and highways, could reinvigorate a nation of displaced employees.

Krisiloff points to policy programs that are different from basic income but similar in that they bridge political parties, like the federal earned income tax credit (EITC). With an EITC, low- to moderate-income families earn a much larger refund when they file their taxes than they would without it — the idea being that people will want to find a job, since it rewards them come tax season.

What remains to be seen in the coming decades is whether current trends of automation hold.

Basic income has proven successful in past experiments, but the extent to which it uplifts displaced American workers all depends on whether we change our attitudes to prioritize employee satisfaction over pure profit.

Collectively, those decisions will determine how quickly and to what degree robotics replace the most vulnerable people: the long-haul truck drivers, fast-food employees, customer service reps, and so on.

If basic income does end up being the hero that saves American workers, Pugh still advises people to value the entrepreneurial spirit.

"It's not going to make everything easy for you," he says. "But it means if you're stuck in a crappy business relationship, you have an opportunity to step away from that and know that you won't be homeless."