Why economists are at war over inequality

According to a familiar saying, academic disputes are so vicious precisely because the stakes are so low. But in a scholarly battle over inequality, the stakes are rather higher. Research by a trio of French economists—Thomas Piketty, Emmanuel Saez and Gabriel Zucman—has popularised the notion that American income inequality is soaring. Other economists have built heaps of research upon these findings, while politicians have pledged to undo the trends through higher taxes and spending. To most people the phrase “inequality is rising” seems self-evidently true.