The price of crude oil in the U.S. never exceeded $40 per barrel until mid-2004. By 2006 it reached$70, and in July 2008 it peaked at $145. By late 2008 it had plummeted to about $30 before increasingto $110 in 2011. Are speculators at least partly to blame for these sharp price changes? We...

This paper tests and confirms the existence of a puzzling phenomenon - the prices of largely unrelated raw commodities have a persistent tendency to move together. We show that this comovement of prices is well in excess of anything that can be explained by the common effects of past, current,...

The idea that wages rise relative to alternatives as job seniority accumulates is the foundation of the theory of specific human capital, as well as other widely accepted theories of compensation. The fact that persons with longer job tenures typically earn higher wages tends to support these...