Could machines really steal jobs?
Gates thinks so.
He's concerned for the millions of people working in jobs likely to see automation – in factories and warehouses, truck and taxi drivers – and whether they will be able to find work if robots take away their jobs.
In an interview with the Quartz, Gates said industries and governments need to start looking into the social consequences of replacing people with robots.
Gates's suggestion has technology buffs concerned.
His comments come at a time when US President Donald Trump has ignited debate on how people are tired of the government's inability to stem job losses and address growing income inequality.
The tech billionaire and philanthropist has proposed an additional tax on companies where robots replace humans. Gates said the tax revenue should be used to train people for jobs that are available.
There will always be work where human interaction is important, such as teaching and nursing, Gates said.
A robot tax, really?
Companies that automate production and services will pay the tax, Gates explains.
But these companies will also be saving as they won't pay income tax, contribute to social security and have disability insurance. This means that despite the tax, they will still see increased profits.
Should people be afraid of technology?
The threat that new technology will take away jobs from humans goes back 200 years.
But recent technological advancements have raised anxiety. Half of the jobs in developed countries such as the US are at risk of being automated, research from Oxford University shows.
There was a time when telephone companies employed people to operate switchboards but then came automated systems, ending the need for humans. Tractors and mechanical harvesters forced millions of farmers to migrate to cities.
It's not just assembly-line jobs that the fast-learning algorithms threaten to take over. It seems the work that requires human thinking and knowledge will also be taken over by computers in a few years.
University-educated radiologists now face being replaced by computers that can analyse images accurately and faster, writes Martin Ford in his book Rise of the Robots.
But is automation all that bad?
Opinion is divided.
Critics argue that slowing down automation could stall growth and hurt the economy. And machines are more efficient and can produce more.
There are some like financial columnist, Matthew Lynn, who argue that technology that destroys jobs has the potential to create new ones.
"Gates, who destroyed the typing pool with word-processing software, should know that better than anyone." Microsoft Word helped millions of people become writers and online content developers.
The Economist said Gates's proposal could help maintain social stability but it would also mean higher costs for services such as healthcare.
Gates's backers say immediate action needs to be taken.
Quincy Larson, who runs the Free Code Camp, said in his blog that the threat of automation displacing millions of workers is very real.
He cites the example of Amazon Go stores where people can pick up their groceries without going through cashier lines. The bill is charged automatically to a customer's Amazon account.
This Wired video shows the efficiency gains warehousing companies can have by employing robots
Workers should be trained for emerging engineering jobs such as programming work with a portion of taxpayers' money that at the moment is used to subsidised industry, Larson said.
Do other tech giants support Gates?
He has some support.
Business tycoon, Elon Musk, who is at the forefront of self-driving vehicle technology, also wants a safety net for people who are replaced by robots.
The founder of Tesla suggests a universal basic income for people who become unemployed as a result of automation.
"There would be fewer and fewer jobs that a robot can't do better," he told a conference recently. "These are not things that I wish to happen. These are things that probably will happen."
In Europe, politicians are already discussing the repercussions of increased automation.
French presidential candidate Benoit Hamon won the primaries of his socialist party on the back of a promise to establish a universal pay of $810 – funded by a tax on industrial robots.
Former Greek Finance Minister Yanis Varoufakis is also a strong believer of "civilising capitalism."
"If you take an iPhone apart, every single technology in it was developed by some government grant, every single one," he said at a discussion with Noam Chomsky last year.
Earlier, a Luxembourg politician, Mady Delvaux said in a report that basic income could be funded by a tax on robots.