Nicholas D. Kristoff: Inequality

MILAN, ITALY - NOVEMBER 10: Joseph Stiglitz delivers a speech at the World Business Forum 2011 on November 10, 2011 in Milan, Italy. International business executives attended the eighth edition of the World Business Forum, an annual global business summit, which will run from November 9-10. (Image credit: Getty Images via @daylife)

Our wealth has become so skewed that the top 1 percent possesses a greater collective worth than the entire bottom 90 percent, according to the Economic Policy Institute in Washington.

This inequality is a central challenge for the United States today and should be getting far more attention in this presidential campaign. A few snapshots:

• The six heirs of Sam Walton, the founder of Walmart, own as much wealth as the bottom 100 million Americans.

• In 2010, 93 percent of the gain in national income went to the top 1 percent.

• America’s Gini coefficient, the classic measure of inequality, set a modern record last month — the highest since the Great Depression.

This dismal ground is explored in an important and smart new book, “The Price of Inequality,” by Joseph Stiglitz, the Nobel laureate who was chairman of the Council of Economic Advisers under President Bill Clinton. It’s a searing read.

“We are paying a high price for our inequality — an economic system that is less stable and less efficient, with less growth,” Stiglitz warns.