NEW YORK (MainStreet) - The rich aren't coming to save us.

Last year one of the biggest stories in the food industry was the sell-off of Red Lobster by Darden Restaurants. The news was followed quickly by reports on the struggles of Olive Garden, a brand which recently posted its first profitable quarter since 2010, and the sudden prominence of mid-cost fast food like Five Guys and Chipotle.

A pattern seemed clear: the middle has fallen out of the food industry, just as it has in retail. While dollar stores and ritzy boutiques thrive, mid-range stores like the Gap and Best Buy struggle to keep locations open. In once vibrant neighborhoods like Chicago's Lincoln Park and Lakeview, solidly middle class, young professional areas, row after row of shuttered storefronts are testament of just how quickly the oxygen has been sucked out of the retail market even in one of the nation's wealthiest cities.

Many commenters have been quick to blame the decline on e-commerce. They, including many voices within the industry, see the market as simply struggling for a more competitive and discerning consumer. "We don't need our customers to spend more," Macy's CEO Terry Lundgren told the Dallas Morning News last year in an interview. "We need them to spend more with us." The result has been a barrage of sales that often leave retailers worse off than ever, as stores post 40% off deals just for a chance to keep people coming in the door.

That might work for a market bartering over more discerning consumers, but what if consumers haven't gotten pickier? What if they've just gotten poorer?

Inequality has become one of the main economic stories of our era, and according to an analysis by the Center for American Progress, a left-leaning think tank, it's also a driving force behind the middle class retail squeeze. Mid-range options are struggling, because their customers simply have less money, and often carry more debt. Wage stagnation and increasing costs of living have left the median family with approximately $5,500 less disposable income per year than in 2000.

Student debt, a feature in most young people's lives, takes on average another 7% of their income, money that would otherwise be spent.

The result is a consumer market left generally poorer, and one that consequently spends less. Even now, a couple years after the nominal end of the Great Recession, retail sales continue to struggle. Per-person spending remains 14% below its pre-recession trend, a dip concentrated almost entirely in the middle.

"We've had a recovery since June 2009, and we've had GDP growth since then, but retail sales have been really bad," explained Brendan Duke, an economist with the Center for American Progress and author of the report The Rich Can't Save Retail. "They're very far away from their pre-Great Recession trend. One [reason] is the fact that the GDP growth and income growth has been really concentrated at the top."

As a result, Duke postulates, retailers who appeal to people who've been making money -- those at the very top -- have been doing well. What's more, retailers that appeal to people at the very bottom have been doing well. It's the mid-market retailers that feel the squeeze. But the 1% spending spree can't be the panacea.

Duke's argument is that inequality is very bad for the retail sector, as it concentrates money in the hands of fewer potential shoppers. The result is a general dying out of any stores that don't cater to either wealthy tastes or rock bottom means.

Take Walmart, for example, Duke argued. From 2010 to 2013, the superstore had a sales growth of 3%, "which was basically population growth. Walmart is struggling with this. They're losing business to dollar stores, because Walmart has become too expensive for a lot of consumers."

Duke backs up his theory with an economist's battery of statistics. Personal consumption has dropped overall, he said, which means it hasn't merely fled online or to urban boutique stores. The impact of that decline has also been concentrated; while most of the nation lags, the wealthiest 5% of households are fully back to their pre-recession spending habits.

Skyrocketing inequality has allowed those households to recover their spending power, while the average consumer has taken a functional spending cut over the same time period. Although the U.S. economy has rebuilt the wealth lost in the recession, it sits in fewer, deeper pockets than ever before. From a retailer's perspective that's a big problem, because there's only so much shopping that any one customer will do, no matter how wealthy.

"To some extend we shouldn't care whether people go shopping at Bloomingdale's or Macy's," Duke acknowledged, "a dollar is a dollar. But the rich actually can't spend as much as the middle class could."

"And if the money is not being spent, then there's not an opportunity to gain it," he added.

The example is hypothetical but straightforward. A wealthy banker, even one who shops at the Gap rather than its up-brand cousin Banana Republic, only needs to wear so many jeans. Once he's filled his closet, extra paychecks will go into a savings account. Sitting in a savings account that money may, debatably, fuel investment capital, but it won't help the retail sector out at all. Meanwhile this banker's barista would most likely take an extra $50 and get a new pair of jeans right away.

This savings gap costs retailers approximately 35 cents on the dollar.

Between 2010 and 2012, households in the bottom 90% of incomes saved almost nothing while the top 1% of earners saved more than 35% of their income. For retailers, every penny saved is a penny they don't get to earn. At a savings rate of 35%, every dollar that goes to the top 1% means only 65 cents spent back out into the economy.

This would be less of a problem, except that almost all of the new wealth created after the recession has gone to that top 1%.

Retailers have responded to their new circumstances by doubling down on the extremes.

Some 68% of industry filings identify flat or falling disposable incomes as a risk to their business model, and many have begun snapping up luxury brands to shore up their finances. While grocery giant Kroger snapped up the high-end market Harris Teeter, Darden Restaurants has watched its Capital Grille steakhouse boom.

Other companies have begun to rely on their low-end brands, such as Gap, Inc.'s increasing reliance on Old Navy to cover for the flagship store's sagging profits and closing branches. Even that, however, isn't enough to make up the difference. Between 2010 and 2013, sector growth was dominated by self-identified "off-price" retailers Ross Stores and TJ Maxx (23.14% and 18.28% growth, respectively), as well as Nordstrom (21.68% growth).

In the same three years that JC Penny took a 36.78% loss, Dollar General and Family Dollar grew by more than 25% each.

Most shoppers won't be surprised to hear that retailers are struggling to keep up with the new economy. Shuttered storefronts have become a standard feature of our city sidewalks, and once they're empty they seem to stay that way. Laying the blame at the feet of a new economy, however, may be premature.

Maybe Americans just have less money.

-Written for MainStreet by Eric Reed, a freelance journalist who writes frequently on the subjects of career and travel. You can read more of his work at his website A Wandering Lawyer.