The Brookings Institution issued a report yesterday on income inequality in the U.S.’s 50 largest cities (available here). The report measures inequality by the “95/20 ratio”, which

represents the income at which a household earns more than 95 percent of all other households, divided by the income at which a household earns more than only 20 percent of all other households.

The estimated 95/20 ratio for the city of Seattle in 2012 was 9.2, just a bit above the 9.1 ratio for the nation as a whole. The 95 percent cutoff for Seattle was $239,549, which was 5th highest among the 50 cities. Seattle’s 20 percent cutoff was $26,156, which was 3rd highest. The three cities with the highest measured inequality were Atlanta (18.8), San Francisco (16.6) and Miami (15.7). The three cities with the lowest inequality were Mesa, Arizona (7.5), Arlington, Texas (7.3), and Virginia Beach, Virginia (6.0).

Seattle’s ratio declined slightly from 2007 to 2012, while nearly every other city’s ratio increased. The author of the report suggests – without providing any evidence – that this might be because of the migration of poorer households from Seattle to south King County. It seems likely to me that migration of high earners into the city is a bigger part of the story. Seattle ranked 14th of the 50 cities in population growth from 2007 to 2012.