Angus Deaton-- one of the foremost experts on economic development and on poverty-- tells the remarkable story of how, starting two hundred and fifty years ago, some parts of the world began to experience sustained progress, opening up gaps and setting the stage for today's hugely unequal world. Deaton takes an in-depth look at the historical and ongoing patterns behind the health and wealth of nations, and he addresses what needs to be done to help those left behind.