Thaya Knight, associate director of financial-regulation studies at the Cato Institute, isn't exactly jumping for joy over the Securities and Exchange Commission's approval of a rule last week to make public companies disclose the ratio of CEO pay to that of the company’s median employee.

The rule, of course, stems from growing public concern about income inequality. According to the Economic Policy Institute, CEOs' pay totaled almost 300 times that of their employees in 2013, up from 20 in 1963.

"It is difficult to think of another SEC rule with so little redeeming value," Knight writes in The Wall Street Journal. "The rule is unrelated to the SEC’s mission, imposes significant costs on public companies and will do little to achieve its intended goals."

It's not the SEC's job to make companies narrow the pay gap between executives and workers, she says. And making companies reveal pay ratios won't help regular workers in any case, as companies are likely to jettison their lowest-paid employees to boost the average.

Elsewhere on the income inequality front, one virtue in this country has always been our social mobility — that poor people can grow up to be rich people by dint of hard work. But that virtue may be sliding into vice, says New York Times columnist Nicholas Kristof.

"We like to boast of America as the land of opportunity, and historically there is truth to that," he writes. "Yet I fear that by 2015 we’ve become the socially rigid society our forebears fled, replicating the barriers and class gaps that drove them away."

Various studies show that Canada and many European countries have more social mobility than we do. A recent study by The Pew Charitable Trusts found that a child born in the bottom 20 percent of the United States by income has only a 4 percent chance to climb to the top 20 percent.

The lack of opportunity for the poor is particularly distressing at time when 22 percent of Americans live in poverty, up from 18 percent at the onset of the financial crisis in 2008, Kristof says.

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