A Nobel economics prize goes to pioneers in understanding poverty

THE MOST important question in economics is also the hardest: why do some countries stay poor while others grow rich? In 2015, 10% of the world’s population lived on less than $1.90 per day, down from 36% in 1990. But more than 700m people remain in extreme poverty, and the number grows every day in certain parts of the world, in particular sub-Saharan Africa. For their contributions to understanding gaps in development, the better to close them, Abhijit Banerjee, Esther Duflo and Michael Kremer have been awarded this year’s Nobel prize for economics. All three are Americans, though Mr Banerjee and Ms Duflo are immigrants (and married to each other). Ms Duflo is only the second woman to have received the prize and, at 46, the youngest winner ever.