In the late 1970s, a half-century trend toward growing income equality reversed itself. Ever since, U.S. incomes have grown more unequal. Middle-class incomes stagnated while the top 1 percent’s share of national income climbed to 24 percent. Middle-income workers no longer benefit from productivity increases, and upward mobility, long the saving grace of the American economy, has faltered. Why is this happening? In the following 10-part series, Slate’s Timothy Noah weighs eight possible causes of what Princeton economist Paul Krugman has labeled the Great Divergence. This 30-year trend “may represent the most significant change in American society in your lifetime,” Noah writes, “and it’s not a change for the better.”

In the late 1970s, a half-century trend toward growing income equality reversed itself. Ever since, U.S. incomes have grown more unequal. Middle-class incomes stagnated while the top 1 percent’s share of national income climbed to 24 percent. Middle-income workers no longer benefit from productivity increases, and upward mobility, long the saving grace of the American economy, has faltered. Why is this happening? In the following 10-part series, Slate’s Timothy Noah weighs eight possible causes of what Princeton economist Paul Krugman has labeled the Great Divergence. This 30-year trend “may represent the most significant change in American society in your lifetime,” Noah writes, “and it’s not a change for the better.”

Part 1

Introducing the Great Divergence: Trying to understand income inequality.

Part 2

The Usual Suspects Are Innocent : Neither race nor gender nor the breakdown of the American family created the Great Divergence.

Part 3

Did Immigration Create the Great Divergence? Why we can’t blame income inequality on the post-1965 immigration surge.

Part 4

Did Computers Create Inequality? No. The tech boom’s impact was no greater than that of previous technological upheavals during the 20th century.

Part 5

Can We Blame Income Inequality on Republicans? Yes, but for the very richest beneficiaries the trend has been bipartisan.

Part 6

The Great Divergence and the Death of Organized Labor : How has the decline of the union contributed to income inequality?

Part 7

The Great Divergence and International Trade : Trade didn’t create inequality, and then it did.

Part 8

The Stinking Rich and the Great Divergence: Executive compensation took off in the 1980s and 1990s. Is it to blame?