The world has achieved its first Millennium Development Goal of cutting extreme poverty in half ahead of the 2015 deadline, a study by the World Bank shows. The bank defines extreme poverty as living on under $1.25 per day, adjusted for purchasing power parity. According to the report, released this week, 1.29 billion people, or 22 per cent of the developing world’s population, live below $1.25 a day, down from 52 per cent in 1981.