Each fall, Forbes magazine publishes a list of the four hundred richest Americans. For over a decade, Microsoft founder Bill Gates III has topped the list, as he did in 2008, when Forbes estimated his net worth at $57 billion. Other members of the club include investor Warren Buffett (ranked 2nd, with $50 billion), the owners of Wal-Mart, the founders of Google and Amazon, assorted oilmen, hedge fund managers, media moguls, and real-estate tycoons, television talk show host Oprah Winfrey (in 155th place, with $2.7 billion), and New York Yankees owner George Steinbrenner (tied for last place, with $1.3 billion).

So vast is the wealth at the top of the American economy, even in a weakened state, that being a mere billionaire is barely enough to gain admission to the Forbes 400. In fact, the richest 1 percent of Americans possess over a third of the country's wealth, more than the combined wealth of the bottom 90 percent of American families. The top 10 percent of American households take in 42 percent of all income and hold 71 percent of all wealth.

Economic inequality is steeper in the United States than in other democracies. Some people think that such inequality is unjust, and favor taxing the rich to help the poor. Others disagree. They say there is nothing unfair about economic inequality, provided it arises without force or fraud, through the choices people make in a market economy.

Who is right?