One of the most talked about economics books of the last few years is Thomas Piketty's Capital in the Twenty-First Century. It is not hard to see why. Piketty, an economics professor at the Paris School of Economics, argues that wealth inequality, which is already high, will increase in the coming decades and he advocates much higher taxes on the wealthy. That taps into people's strong emotions about the "top 1 percent"--a popular topic of discussion in recent years.