Persistent productivity gains to rural-urban migrants have been documented by a number of researchers. One interpretation of this result is that individuals learn higher value skills in cities than they would have learned in less dense areas. Another explanation for this result, however, is that...

We analyze the role of optimal income taxation across different local labor markets. Should labor in large cities be taxed differently than in small cities? We find that a planner who needs to raise revenue and is constrained by free mobility of labor across cities does not choose equal taxes...