How Not to Count the Poor

This chapter argues that the World Bank's approach to estimating the extent, distribution, and trend of global income poverty is neither meaningful nor reliable. The Bank uses an arbitrary international poverty line that is not adequately anchored in any specification of the real requirements of human beings. Moreover, it employs a concept of purchasing power 'equivalence' that is neither well defined nor appropriate for poverty assessment. These difficulties are inherent in the Bank's 'money-metric' approach and cannot be credibly overcome without dispensing with this approach altogether. In addition, the Bank extrapolates incorrectly from limited data and thereby creates an appearance of precision that masks the high probable error of its estimates. It is difficult to judge the nature and extent of the errors in global poverty estimates that these three flaws produce. However, there is reason to believe that the Bank's approach may have led it to understate the extent of global income poverty and to infer without adequate justification that global income poverty has steeply declined in the recent period. A new methodology of global poverty assessment, focused directly on what is needed to achieve elementary human requirements, is feasible and necessary. A practical approach to implementing an alternative is described.