Private-Equity Pigs

Is there something Henry Kravis wants but can't afford to buy? Seems unlikely: according to Forbes, he's worth $2.6 billion. So is he addled by greed or what? Kravis, Stephen Schwarzman and other princes of private equity (the financial deal of the moment) have been visiting Congress and wielding their checkbooks in an effort to save a tax-code provision that allows them to pay an income tax of 15% rather than the normal top rate of 35%. Have they lost their minds?

Ordinarily, the concept of greed isn't very useful in trying to understand the economy. We are all greedy. We'd all like...