What is a robot exactly – and how do we make it pay tax?

A tax on robots is one of those ideas that sounds attractive, and when it's put forward by someone with the credibility of Bill Gates, as it was in a recent interview with Quartz magazine, you can guarantee it will generate a lot of interest. If he, of all people, says taxing robots is a good idea, then surely it is worth considering? At first pass, the idea feels like common sense. After all, if robots replace workers but don't generate tax revenue, it means not only that the funds available for government services are substantially diminished, but that inequality – already at record levels in developed nations – is likely to increase. Wages that would have been earned by human workers, now displaced by robots, will go straight to profits, increasing the wealth gap between those who own the robots and the growing pool of unemployed workers.