Bill Gates thinks robots should pay taxes. My first reaction was: Mr Gates obviously doesn’t know much economics. If he did, he would know that things do not pay taxes. Only people do.
Robots, so I thought, are machines. They don’t have an income of their own, they don’t consume stuff. The income they help produce goes to whoever owns the robot. If I own a robot, my willingness to let it (him? her?) work for a firm increases with the robot wage rate, the amount of money I receive per hour of work done by my robot. A tax on robot wages would shift the supply curve of robot labor up (or, if you prefer, to the left), increasing for each given amount of robot labor the wage rate employers must pay to get it. The gross robot wage increases, although probably by less than the tax rate, depending on how elastic the demand for robot labor is. Assuming that the demand elasticity is not infinite, the tax burden will be split between the robot owners and the employers of robots. So the robot tax would just be another form of a capital tax, which would partly be shifted to other factors of production, including human labor. In no real sense would it „tax robots“.
Now there are good reasons to believe that we are approaching the “technological singularity“, a scenario in which robots become smarter than humans. Some experts on artificial intelligence reckon we might be only 30 years away from that. I have exactly zero qualifications to judge the plausibility of that claim, but I don’t see any obvious reason why it couldn’t happen.
Suppose the singularity does happen. Then it seems quite ridiculous to assume that humans own robots. More likely, it would be the robots who own humans. Indeed, we can only hope the super-intelligent robots would treat us a little better than we are treating less intelligent life-forms now. Let’s assume, for the sake of argument, that humans will co-exist with the super robots as equals, at least for a while. Then robots would effectively become another class of people competing with us in the market place for jobs and goods. In such a world, robots are capable of bearing a tax in the sense that they would have to cut back on their consumption (whatever it is robots consume) when faced with a tax. But even in this, admittedly unlikely, scenario, it would be the case that humans feel some of the burden of the robot tax. This is because even super-intelligent robots will react to incentives. Why, given that they are super intelligent, they should react much better to incentives than homo sapiens with all its cognitive biases. If we tax their labor, they will supply less of it, which hurts humans.
So yes, robots could pay taxes. But only if they are intelligent and powerful enough to resist being held as slaves by humans, and not as intelligent and powerful as would allow them to enslave humans. Not a very likely scenario I guess.
PS: If you are curious what AI is currently capable of doing, here is some AI-produced poetry.