The number is impressive: $17.5 trillion. That's the total of U.S. retirement assets, according to the Investment Company Institute, a Washington D.C. trade group. It's up by 9.1% for the year. Still, looking at the data, it's striking that the figure is below 2007. It's taking more than three years to repair the damage from the downturn, let alone build up a bigger nest egg.

Retirement savings account for more than a third (37%) of all household financial assets at the end of last year.

What's more, housing wealth has vaporized for many households. More than 27 percent of all residential properties with a mortgage--13.4 million homeowners--had negative-equity or near-negative-equity mortgages at the end of 2010, according to CoreLogic, an information and analytics firm. I doubt that the number will improve much anytime soon considering the drop in home prices so far this year.

The combination of poorly performing retirement portfolios and an unhealthy housing market still weighs on the economy. Little wonder households are reluctant spenders.

Follow Chris Farrell at @cfarrellecon