Does the Great Divergence reflect racial inequality between whites and blacks? That's a good guess, considering the median annual income for black families in the United States is 38 percent lower than the median income for white families. Even so, it's wrong.

Yes, there's a sizable (and worrisome) gap between incomes for blacks and whites. But as this chart demonstrates, the relationship between median black income and median white income has scarcely changed since 1973. In 1973, blacks made 58 cents for every dollar whites made. In 2008 they made 62 cents. For black-white inequality to influence the Great Divergence, the gap would have to have widened significantly, and it hasn't—at least as measured by family income, the principal metric for the Great Divergence. The median Hispanic income relative to white income is also virtually unchanged, though there's been a bit more movement up and down. The only major change relating to ethnic groups has been for Asians, who started out more prosperous than whites ($1.14 for every white dollar) and became more so ($1.18 for every white dollar*), with some ups and downs in between, during a shorter time period.

We don't mean to suggest it's peachy that the black-white income gap (and the Hispanic-and-white gap) hasn't changed in 30 years. These are serious social problems. They just aren't problems that have anything to do with the Great Divergence.

Correction, Sept. 29, 2010: An earlier version of this slide misreported the ratio of Asian median income to white median income in 2008 as $1.82. In fact, it was $1.18.

The Great Divergence In Pictures: A visual guide to income inequality.

By Timothy Noah

The Great Divergence

Posted Friday, Sept. 3, 2010, at 1:49 PM ET