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.

Rising inequality hasn't really accomplished anything of value for its ostensible beneficiaries, the top one percent. They've all built bigger mansions and staged more lavish parties. But in so doing, they've simply raised the bar that defines what's considered adequate in these categories.

Questions like, "Is my suit OK?", or "Is my job performance satisfactory?", are impossible to think about in the absence of a suitable frame of reference. For an interview suit to serve its purpose, it must make you look good relative to other candidates for the job you want. For your job performance to be satisfactory, it must compare favorably with the performance of others who want the same promotion you do. As Charles Darwin saw clearly, much of life is graded on the curve, and conventional economic models completely ignore that fact.

Only the federal government has the power to spend beyond its current revenue. It shouldn't do that when the economy is at full employment. But it's an essential step for an economy mired in recession.

Many decry rising inequality because it makes those who've fallen behind feel impoverished. But it's done much more than cause hurt feelings. It has also raised the real cost to middle-income families of achieving many basic goals. The process begins with the completely unremarkable fact that top earners have been spending at a substantially higher rate than before. They've been building bigger mansions, staging more elaborate weddings and coming-of-age parties for their kids, buying more and better of everything.

One reason that might motivate a worker to accept a riskier job at higher pay, for example, would be that doing so would enable him to bid more effectively for a house in a better school district. But if other workers did likewise, none would achieve the goal they were striving for.