In response to the Great Recession, the federal government spent hundreds of billions of dollars in tax and other interventions in the labor market as part of the stimulus and follow-up policies. Policymakers traditionally have based their policies on Keynesian theories that recessions are driven by inadequate demand, so that increasing government spending will increase demand for economic activity and workers. However, these theories guide how much to spend, not how to design the spending. As a result, despite this massive outlay of funds, the theory for the form that labor income taxes and related policies should change during recessions is surprisingly poorly developed. Instead of drawing on Keynesian macroeconomic theories, we draw on...