Not as linked as we thought, according to Jordan Weissmann at the Atlantic.

Money quote:

The working paper, from Professors Christopher Meissner of the University of California, Davis and Michael Bordo of Rutgers, looks at whether there is a consistent historical relationship between rising income inequality and financial crises, using economic data on fourteen countries, including the United States, from between 1920 and 2008. It finds that although big financial busts tend to follow on the heels of credit booms like the mortgage bubble, there is no statistical relationship between the expansion of credit and the share of a country’s income going to it’s top 1 percent.