From a new Ad Age white paper, with projections on the 2010 Census:

“The concept of an ‘average American’ is gone, probably forever,” demographics expert Peter Francese writes in 2010 America, a new Ad Age white paper. “The average American has been replaced by a complex, multidimensional society that defies simplistic labeling.”

The message to marketers is clear: No single demographic, or even handful of demographics, neatly defines the nation. There is no such thing as “the American consumer.”

“This census will show that no household type neatly describes even one-third of households,” Mr. Francese writes. “The iconic American family — married couple with children — will account for a mere 22% of households.”

The most prevalent type of U.S. household? Married couple with no kids, followed closely by single-person households, according to Mr. Francese’s projections.

More projections:

80% of people age 65-plus will be white non-Hispanics. But just 54% of children under age 18 will be white non-Hispanics. Mr. Francese observes: “White non-Hispanics will surely account for fewer than half of births by 2015.” In 2010, Hispanics will be both the nation’s fastest-growing and largest minority (50 million people).

And (unsurprisingly) the nation is increasingly mobile

Over the past decade … 85% of the nation’s population growth occurred in the South and West. “During the still-nameless decade from 2000 to 2010, a total of about 3 million people have moved out of the Northeast, and another 2 million have left the Midwest” for the South and West.

via The ‘Average American’ Is Dying Off.