In 1992, the 400th richest person in America made $24 million. In 2007, the 400th richest person in America made $138 million (or $87 million, inflation-adjusted). Now, that almost certainly wasn't the same guy. There's a lot of churn at the top of the money pyramid. In all of the 1990s, only 25% of the Fortunate 400 made more than one appearance. But the overall message is the same. The rich keeping getting richer. According to the IRS, which recently released 2009 data from the 400 richest individual income tax returns, the real runaway growth in wealth has come from...