Both Sanders' plan to fund Medicare for All and Warren's plan are based on continuing the current practice in which businesses pay per employee. However, making businesses pay per employee creates an artificial pressure to reduce employment — for instance, to invest in automation. That is an undesirable side effect, and a very important one.

We ought to replace all per-employee taxes with a progressive tax on business income. This would eliminate the pressure to replace humans with robots and also promote competition by imposing higher tax rates on large companies.