Is inequality really a problem for U.S. economic growth?

Economist Robert Gordon recently wrote a paper in which he asked the provocative question, “Is U.S. economic growth over?”  And he identifies income inequality as one of “headwinds”  facing the economy:

The most important quantitatively in holding down the growth of our future income is rising inequality. The growth in median real income has been substantially slower than all of these growth rates of average per-capita income discussed thus far. The Berkeley web site of Emmanuel Saez provides the startling figures. From 1993 to 2008, the average growth in real household income was 1.3 percent per year. But for the bottom 99% growth was only 0.75, a gap of 0.55 percent per year. The top one percent of the income distribution captured fully 52% of the income gains during that 15-year period. If what we care about when we talk about “consumer well being” is the bottom 99 percent, then we must deduct 0.55 percent from the average growth rates of real GDP per capita presented here and elsewhere.

Wait, I thought the paper was about slowing innovation, not wealth redistribution. Moreover, is there really much evidence that income inequality hurts economic growth in advanced economies? Scott Winship has his doubts, finding “scant evidence” that it’s indeed the case in advanced economies:
There are plenty of reasons to worry about inequality of opportunity — socioeconomic gaps in college-going are on the rise, and test-score gaps between rich and poor kids have similarly increased, to name just two examples. But the evidence that these problems would diminish if we could limit the top 1 percent’s incomes to those seen in other countries is nonexistent. (Incidentally, the incomes of the top 1 percent have been on the rise in our peer nations too, and middle-class income growth has slowed in those countries as well.)

Read more: http://www.aei-ideas.org/2012/10/is-inequality-really-a-problem-for-u-s-economic-growth/