Niall Ferguson: “Welcome to Obama’s America: nearly half the population is not represented on a taxable return—almost exactly the same proportion that lives in a household where at least one member receives some type of government benefit. We are becoming the 50-50 nation—half of us paying the taxes, the other half receiving the benefits.”

Journalist: It is true that 46 percent of households did not pay federal income tax in 2011. It is not true that they pay no taxes. Federal income taxes account barely account for half of federal taxes, and much less of total taxes, if you count the state and local level. Many of those other taxes can be regressive. If you take all taxes into account, our system is barely progressive at all.

But why do almost half of all households pay no federal income tax? Because they don’t have much money to tax. Here’s the breakdown from the nonpartisan Tax Policy Center. Half of these households are simply too poor — they make under $20,000 — to have any liability. Another quarter are retirees on tax-exempt Social Security benefits. The remaining households have no liability because of tax expenditures like the earned-income tax credit or the child credit.

In other words, the poor, the old, and children. Not exactly the “50-50 nation” of makers and takers — or “lucky duckies” — that Ferguson imagines.

As psychologists will tell you, fear of loss is more powerful than the prospect of gain. The struggling middle classes look down more anxiously than they look up, particularly in recession and sluggish recovery. Polls show they dislike high income inequalities but are lukewarm about redistribution. They worry that they are unlikely to benefit and may even lose from it; and worse still, those below them will be pulled up sufficiently to threaten their status. This is exactly the mindset in the US, where individualist values are more deeply embedded. Americans accepted tax cuts for the rich with equanimity. Better to let the rich keep their money, they calculated, than to have it benefit economic and social inferiors.

As Runciman observed, “most people’s lives are governed more by the resentment of narrow inequalities, the cultivation of modest ambitions and the preservation of small differentials” than by the larger picture of social justice. That applies as much to the professional as to the working classes.