What shall we do when the robots take our jobs? Last week’s column discussed mass technological unemployment, and readers were quick to write in with variants on the same common sense suggestion: tax the robots.

“Give a robot a deemed income equivalent to the wage of the human it is replacing, with a default of the average income,” wrote one. A similar suggestion: “If one robot displaced five people earning a modest ￡20,000 each, then that robot could be said to have an economic value of ￡100,000 per annum.” Both correspondents proposed an income tax or similar levy on this robot-generated output.

I’m grateful for all constructive comments, but particularly grateful for these because I think they are wrong in a fascinating and instructive way. The fault is mine: I set a trap every time I talk about “robots” and “jobs”. That is not how automation happens.