Kenneth Arrow in the Boston Review:
The specific problems of the current U.S. economy—the drastic increase in unemployment and sluggish increase in output—overlay a tendency of much longer duration, a drastic and rapid increase in the inequality of income. Every economy of complexity produces an unequal distribution of the good things in life. But the period immediately following World War II showed a considerably increased equality of income compared with either the Great Depression or the previous period of relative prosperity.
Since the middle 1980s, this tendency has been reversed. In the United States, median family income (adjusted for size) has remained virtually constant since 1995, while per capita income has risen at about 2 percent per annum. The difference in income between college graduates and those with only high school degrees increased at a rapid rate, even during the period before 1990 when per capita income grew very slowly. Further, the proportion of the college-age population enrolled in college, which had been rising rapidly, stopped increasing and has remained the same for thirty years.
Clearly, the bulk of the gains from increased productivity went to a small group of upper-income recipients. Indeed, closer study has shown that the bulk of the increase went to the top 1 percent of income recipients and much of that to those in the top .1 percent.
More here.