Are the world’s poorest being left behind?

Traditional assessments of economic growth and progress against poverty tell us little about whether the poorest are being left behind—whether the consumption floor is rising above the biological minimum. To address this deficiency, the paper identifies the expected value of the floor as a weighted mean of observed consumptions for the poorest stratum. Under the identifying assumptions and using data for the developing world over 1981–2011, the estimated floor is about half the $1.25 a day poverty line. Economic growth and social policies have delivered only modest progress in raising the floor, despite overall growth and progress in reducing the number living near the floor.