For the three decades after WWII, incomes grew at about 3 percent a year for people up and down the income ladder, but since then most income growth has occurred among the top quintile. And among that group, most of the income growth has occurred among the top 5 percent. The pattern repeats itself all the way up. Most of the growth among the top 5 percent has been among the top 1 percent, and most of the growth among that group has been among the top one-tenth of one percent.

Adam Smith's uncritically enthusiastic modern disciples portray his invisible hand theory as saying that market forces reliably harness selfish individuals to serve the common good. That's often true, but as Darwin recognized clearly, many traits that serve the interests of individual animals make life more difficult for larger groups.

We're in a classic demand-shortfall recession. There aren't enough jobs because total spending is too low. Consumers won't lead the way because they're busy paying down debt and are fearful they'll lose their jobs, if they haven't already. Businesses, which are currently sitting on mountains of cash, won't spend either, because they already have sufficient capacity to produce more than people are willing to buy.

As economists have long noted, the puzzle is not that so few people vote, it's that so many do. After all, no individual's vote has ever tipped the balance in a presidential election.

Many social critics wag their fingers at what they perceive to be frivolous luxury spending. But that misses the point that consumption norms are local. It's not just the rich who spend more when they get more money. Everyone else does, too. The mansions of the rich may seem over the top to people in the middle, but the same could be said of middle-class houses as seen by most of the planet's seven billion people.

The private sector is first of all much larger than the public sector. The waste we see in that sector does not result from the fact that people spend their money carelessly. Mostly, it occurs because what one family must spend to achieve its goals often depends heavily on what other families spend.

It is no exaggeration to say that rising inequality has driven many of the 99 percent into a financial ditch. It also helped spawn the housing bubble that gave us the financial crisis of 2008, the lingering effects of which have forced many OWS protesters to try to launch their careers in by far the most inhospitable labor market we've seen since the Great Depression. Even those recent graduates who manage to find jobs will suffer a lifelong penalty in reduced wages.