The lost last four years

Later figures show that the drop, particularly for median net worth, has occurred since 2007.

Pew Research Center has gotten a lot of attention for this, but they term it as the "Lost Decade."  With median net worth, it is pretty clear that it is just the last four years.

The Wall Street Journal summarizes the dilemma here:

The income of the typical American family—long the envy of much of the world—has dropped for the third year in a row and is now roughly where it was in 1996 when adjusted for inflation.
The income of a household considered to be at the statistical middle fell 2.3% to an inflation-adjusted $49,445 in 2010, which is 7.1% below its 1999 peak, the Census Bureau said. . . .
Earnings of the typical man who works full-time year round fell, and are lower—adjusted for inflation—than in 1978. Earnings for women, meanwhile, are a relative bright spot: Median incomes have been rising in recent years and rose again last year, though women still make 77 cents for every dollar earned by comparably employed men.
The fraction of Americans living in poverty clicked up to 15.1% of the population, and 22% of children are now living below the poverty line, the biggest percentage since 1993. . . .