A new paper by Laurence Chandy and Geoffrey Gertz at the Brookings Institution reports a remarkable acceleration in the pace of progress against absolute poverty since 2005, as can be seen in Figure 1 of their paper (found here). This would be great news if it could be believed, but there are reasons for doubt.
In “updating” the World Bank’s estimates using the Bank’s PovcalNet site, Chandy and Gertz have relied heavily on forecasts rather than estimates based on new surveys. Household surveys are the only credible method of measuring poverty. The technology has improved, but naturally the data take time to collect and process. We still do not have sufficiently recent surveys for many countries, especially in Sub-Saharan Africa, the region with the highest overall poverty rate. The next edition of the World Bank’s regular three-yearly updates of its survey-based estimates of global poverty measures is scheduled for release later this year, and will go up to 2008, and revise consistently back to 1980. (Information on the last update can be found here. The paper documenting the methods and testing their robustness can be found here.)