Gabriel Zucman, a controversial John Bates Clark medallist

global financial crisis of 2007-09 the world has worried more about inequalities of wealth and income. That is in large part a result of work done by a band of French economists, in particular Thomas Piketty, Emmanuel Saez and Gabriel Zucman, which documents a rise in inequality in many countries across recent decades. On May 2nd the American Economic Association awarded Mr Zucman the John Bates Clark Medal, a prize for economists under the age of 40, for his efforts. Other economists usually greet the winner of the Clark medal with a resounding cheer. No one has a bad word to say about Oleg Itskhoki, last year’s winner, who studies exchange rates and the like. They had a slightly different reaction to the announcement about Mr Zucman, who works at the University of California, Berkeley. He is a more divisive figure. Some were delighted; others, rather less so.