Ravallion (2007), “Absolute Poverty Measures for the Developing World, 1981-2004.” Policy Research Working Paper 4211

We report new estimates of measures of absolute poverty for the developing world over 1981-2004. A clear trend decline in the percentage of people who are absolutely poor is evident, although with uneven progress across regions. We find more mixed success in reducing the total number of poor. Indeed, the developing world outside China has seen little or no sustained progress in reducing the number of poor, with rising poverty counts in some regions, notably Sub-Saharan Africa. There are encouraging signs of progress in reducing the incidence of poverty in all regions after 2000, although it is too early to say if this is a new trend