Imagine a giant vacuum cleaner looming over America’s economy, drawing dollars from its bottom to its upper tiers. Using US Census reports, I estimate that since 1985, the lower 60 percent of households have lost $4 trillion, most of which has ascended to the top 5 percent, including a growing tier now taking in $1 million or more each year.1 Some of our founders foresaw this happening. “Society naturally divides itself,” Alexander Hamilton wrote in The Federalist, “into the very few and the many.” His coauthor, James Madison, identified the cause. “Unequal faculties of acquiring property,” he said, inhere in every human grouping. If affluence results from inner aptitudes, it might seem futile to try reining in the rich.

All four of the books under review reject Hamilton and Madison’s premises. All are informative, original, and offer unusual insights. None accepts that social divisions are inevitable or natural, and all make coherent arguments in favor of less inequality, supported by persuasive statistics.

1.

The Spirit Level is a prodigious empirical effort directed to a moral purpose. It ranks the quality of life in twenty-three countries, mainly European, but with Singapore, Israel, and the United States also on the list. To evaluate the well-being of each society, Richard Wilkinson and Kate Pickett use indices ranging from obesity and incarceration rates to teenage births and the feelings people have about their fellow countrymen. They then relate these variables to how income is distributed in each society. Here they deploy the Gini ratio, a three-digit coefficient purporting to measure the extent of income inequality within any grouping for which figures are available. Their national Gini scores range from .230 in egalitarian Sweden to .478 in highly stratified Singapore, with the United States second highest at .450. Linking social indicators to economic disparities, the authors conclude that “reducing inequality is the best way of improving the quality of the social environment.”

As income gaps grow, they write, it’s not only the poor who suffer. Unequal societies not only bear “diseases of poverty,” but also “diseases of affluence.” The latter include cancer and cardiovascular disease as well as the afflictions of well-off people who are “anxiety-ridden,” “prone to depression,” and “seek comfort in overeating, obsessive shopping and spending.” At this point, as elsewhere, the authors tend to get carried away. I’m not sure I’m ready to rank compulsive spending or eating too much as diseases. Even so, Wilkinson and Pickett are blunt in their summary: “inequality is socially corrosive.” What’s missing in their analysis is how far, if at all, income disparities may also degrade the deprived.

The authors don’t go so far as to say that people with above-average…