The post-recession reality is that the customer base for businesses that appeal to the middle class is shrinking as the top tier pulls even further away. In response to the upward shift in spending, PricewaterhouseCoopers clients like big stores and restaurants are chasing richer customers with a wider offering of high-end goods and services, or focusing on rock-bottom prices to attract the expanding ranks of penny-pinching consumers.

In 2012, the top 5 percent of earners were responsible for 38 percent of domestic consumption, up from 28 percent in 1995, the researchers found.

Even more striking, the current recovery has been driven almost entirely by the upper crust, according to Mr. Fazzari and Mr. Cynamon. Since 2009, the year the recession ended, inflation-adjusted spending by this top echelon has risen 17 percent, compared with just 1 percent among the bottom 95 percent.

Investors have taken notice of the shrinking middle. Shares of Sears and J. C. Penney have fallen more than 50 percent since the end of 2009, even as upper-end stores like Nordstrom and bargain-basement chains like Dollar Tree and Family Dollar Stores have more than doubled in value over the same period.

http://www.nytimes.com/2014/02/03/business/the-middle-class-is-steadily-eroding-just-ask-the-business-world.html?ref=business&_r=2