Inflation equals the product of two terms: an extensive margin (the fraction of items with price changes) and an intensive margin (the average size of those price changes). The variance of inflation over time can be decomposed into contributions from each margin. The extensive margin figures...

Externalities play a central role in most theories of economic growth. We argue that international externalities, in particular, are essential for explaining a number of empirical regularities about growth and development. Foremost among these is that many countries appear to share a common long...

Employment and hours appear far more cyclical than dictated by the behavior of productivity and consumption. This puzzle has been called "the labor wedge" -- a cyclical intratemporal wedge between the marginal product of labor and the marginal rate of substitution of consumption for leisure. The...