Income mobility is often thought to equalize permanent incomes and, thereby, to improve social welfare. The welfare analysis of mobility often fails, however, to account for the cost of the variability of periodic incomes around permanent incomes. This paper assesses the net welfare benefit of...

I study the optimal taxation of robots and labor income. In the model, robots substitute for routine labor and complement non-routine labor. I show that while it is optimal to distort robot adoption, robots may be either taxed or subsidized. The robot tax exploits general-equilibrium effects to...