CHICAGO—US government officials announced in the summer of 2009 that the Great Recession was over, and the economy has expanded ever since, if not as fast as most people desired. But Mesirow Financial's chief economist Diane Swonk notes that many of the problems that developed in the run-up to the recession remain, and are sapping the strength of the middle class.

“Structural factors that triggered income inequalities, including a shortfall in skills, technological innovation and increasing globalization, suggest that wages will remain suppressed for the majority of workers for some time to come,” Swonk writes in her latest update on the economy.

Her report cites some good news, such as the decline of the ratio of household debt to income to a pre-recession level, the increasing availability of credit and other beneficial developments. But many of the jobs created since 2009 pay wages too low to support much consumer spending. The decline of real median household income has been sharp and persistent. In 2012 dollars, the median stood at $56,080 in 1999, then fell to $53,285 by 2009, and has kept sinking, hitting $51,017 in 2012.

“Those with wealth and incomes tied to financial assets have regained what they lost to the Great Recession and then some,” Swonk notes, “while the majority of Americans who rely upon their homes as a primary asset are still playing catch-up.”

As reported in GlobeSt.com, Christopher G. Kennedy, the developer of Wolf Point, also raised many of these concerns at the recent Marcus & Millichap CRE Forum, where he said that the specter of income inequality could threaten the US in the long-run.

One result is that while retailers who market luxury or discount goods can look to the future with a great deal of confidence, those who target the middle class have reason to worry. The recent closure of Sears' flagship store on State St., as well as that company's broader financial difficulties, illustrates the situation.

The official end of the recession and the subsequent modest recovery has kicked off a good deal of new retail construction, some of it even aimed at the middle class. But experts say much of this is just pent-up demand that will get satisfied relatively quickly, leaving the underlying problem unsolved.

“The question is what happens after this,” Timothy C. Blum, executive vice president and managing director of HSA Commercial Real Estate's retail brokerage division, tells GlobeSt.com. “The early movers are going to do well, but after that it's going to get risky.”

Swonk points to other signs of underlying problems. For example, “the number of first-time home buyers dropped to 26% of existing home sales in January [and 28% in February], well below the 40% norm, despite a persistently high level of affordability.”

However, the recovery has begun to gather some steam, and Swonk writes that the outlook for 2014 is positive. The cold winter suppressed economic activity, but the coming of spring “will unleash the pent-up demand and the catch-up in construction and manufacturing activity that was delayed by the harsh weather.” Employment and consumer spending will rise, and “investment is also expected to post a moderate comeback, once manufacturing and construction activity bounce back.”