Continuing its slide since the onset of the great recession in December 2007, the U.S. median household income fell by 1.3% from $51,144 to $50,502 between 2010 and 2011, according to data from the U.S. Census Bureau's 2011 edition of the American Communities Survey (ACS).
Even with an upward spike during the last three months of 2011, the median household income has fallen annually since December 2007, when the ACS reported the figure to be $52,673.
Also See: Middle Class was Decade's Biggest Loser
At the end of 2011, the ACS' report, Household Income for States: 2010 and 2011, showed that the median household income ranged a high of $70,004 in Maryland to $36,919 in Mississippi.
Median household incomes were lower than the U.S. median of $50,502 in 27 states and higher in 19 states and the District of Columbia. In North Dakota, Wisconsin, Nebraska and Pennsylvania, median household incomes very close to the overall U.S. median.
Vermont was the only state in which the median household income increased between 2010 and 2011.
The 'Haves' and the 'Have Nots': Are the rich really getting richer and the poor getting poorer? Check the Gini Index. Named for its developer, Italian statistician and sociologist Corrado Gini, the "Gini Index" is a measurement of income distribution and equality within a given geographic area (city, state, nation, etc.). The Gini Index varies between 0.0 and 1.0. A Gini Index value of 0.0 indicates a condition of total income equality where all households in the area have the same income. A Gini Index value of 1.0 indicates a condition of total income inequality, where only one household in the area has any income.
As reported by the Census Bureau, the 2011 Gini Index for the Unites States was 0.475, "significantly" higher that the 0.469 reported in 2010. This increase, states the Census Bureau, indicates more income inequality across the nation.
State-to-state Gini Indexes in 2011 ranged from a high (most income inequality) of 0.534 in the District of Columbia, to a low (least income inequality) of 0.408 in Wyoming.
Between 2010 and 2011, the Gini Index rose - indicating an increase in income inequality -- in 20 states, while remaining statistically unchanged the other states and the District of Columbia.