As demonstrated by the dramatic upward revision of Nigeria’s GDP for 2013, the choice of a benchmark year matters when computing GDP statistics. This column explains how the replacement of benchmark years creates an inconsistency between new and old national accounts series, and how different ways of resolving this inconsistency yield very different estimates of historical GDP levels and growth rates. When used to evaluate the relative historical performance of Spain and France, the interpolation procedure for splicing national accounts produces more plausible results than the conventional ‘retropolation’ approach.
Leandro Prados de la Escosura, 27 September 2014
Joachim De Weerdt, Kathleen Beegle, Jed Friedman, John Gibson, 18 February 2014
Whereas the Millennium Development Goal of reducing extreme poverty by half was achieved by 2010, the global hunger rate has only fallen by a third since 1990. Differences in survey design may account for part of this discrepancy. This column presents the results of a recent experiment in which households were randomly assigned to different survey designs. These different designs yield vastly different hunger estimates, ranging from 19% to 68% of the population being hungry.