By contrast, middle-class Americans remain further behind because whatever wealth they have is derived mainly from home equity. Home prices have only partially recovered from the housing bust. In the first quarter of this year, 18.8 percent of homeowners with a mortgage still owed more on their homes than they were worth, according to real estate data provider Zillow. An additional 18.1 percent have so little equity that it wouldn't be enough to cover closing costs and make a down payment, Zillow calculates.
Fewer Americans even own homes: The home ownership rate fell to 64.8 percent in the first quarter of this year from a peak of 69.2 percent in 2004.
The University of Michigan study found that households at all levels lost wealth during the recession and that not even the top 5 percent have fully regained it.
The study suggests one reason consumer spending growth has been weaker since the recession than before: When people feel wealthier, they're more likely to spend. Most Americans may still feel poorer than before the recession and so may still be restraining their spending.
The losses weren't evenly distributed. For the top 5 percent, net worth fell 16 percent from 2007, just before the recession began, through last year. The net worth of the median household fell much further — 43 percent.
The study paints a bleaker picture of U.S. household wealth than do official figures from the Federal Reserve. The Fed's quarterly report on household wealth has concluded that the nation as a whole regained all the wealth it lost from the recession by the first quarter of 2013.
But the Fed report doesn't break out that data for households at different wealth levels. Its overall figures are lifted by big gains among the wealthiest Americans.
Fabian Pfeffer, assistant research professor at the University of Michigan, said the new study might have found less of an overall wealth recovery than the Fed did because its sample size wasn't big enough to fully capture the richest 2 percent of Americans.