Number of US Occupations Automated Since 1950: 1

While there's a lot of worry about robots replacing American workers, a paper by Harvard economist James Bessen found automation has made humans obsolete in just one job over the past 67 years. Of 270 occupations listed in the 1950 US Census, only elevator operator no longer exists due to automation, Quartz reports. Another 32 jobs were done in by a loss of demand, and five became technologically obsolete. And while machines eventually replaced human operators in the country's elevators, it took them a while. According to NPR, the automated elevator was invented in 1900, but Americans didn't become comfortable with using them for another five decades.

While most of today's jobs could be partially automated in the future, it's unlikely many could be completely taken over by machines. Manufacturing and food service face the greatest threat from automation; management and educational services face the least. However—and while it's not technically an occupation—the American driver could soon go the way of the elevator operator, PC Magazine reports. Surveys have found that less than half of US consumers trust self-driving cars and 25% of US drivers would never ride in one. This sounds an awful lot like the reaction to early automated elevators. In fact, a leading elevator historian calls an elevator without an operator "the Google car of its era." (A robot programmed to avoid humans roams the deserts of California.)