In a speech in Washington on Thursday, the chairman of President Obama’s Council of Economic Advisers said that the American middle class has been shrinking since 1970. Princeton University economist Alan Krueger said the American middle class shrank from 50.3 percent of American households in 1970 to 42.2 percent in 2010. Krueger defined the middle class as households with annual incomes within 50 percent of the national median income. Here is a table presented describing his findings.

 

Later in the speech, Krueger cited well-known studies describing growing income inequality in the United States. His claim about a shrinking middle class, though, appears to be new. While researchers have in the past argued that the middle class is shrinking, both Democratic and Republican administrations have generally steered clear of giving an exact definition of the middle class. Apparently fearing that an exact definition could backfire on them if the economy performs poorly, administrations have vowed to defend the middle class but avoided specifics. Given the central role that the state of the middle class will play in the 2012 presidential campaign, all of that may be different this year. To me, that’s a step forward.