Working Paper
Reckoning Inter-Group Poverty Differentials in the Measurement of Aggregate Poverty

In a heterogeneous population which can be partitioned into well-defined subgroups, it is plausible that the extent of measured aggregate poverty should depend upon the distribution of poverty across the subgroups. A judgment in favour of an equal inter-group distribution of poverty could arise in two ways. In the first approach, equality is upheld as an intrinsic social virtue, and the aggregate measure of poverty, in line with this view, is ‘adjusted’ to reflect the extent of inter-group disparity in the distribution of poverty that obtains. In the present paper, this approach is examined, with specific reference to the advancement of a diagrammatic aid to analysis called the group poverty profile. In the second approach, equality is upheld for instrumental reasons which arise from the observed fact that any individual’s level of deprivation is a function not only of one’s own income, but of the general level of prosperity of the group to which one is affiliated. Individual deprivation functions are specialized to a form which reflects this ‘group-affiliation’ externality, and the resulting poverty measure is studied with respect to its properties, and its implications for inter-group equity. The analysis is briefly extended to a review of the measurement of literacy, along externality-motivated lines suggested elsewhere by Basu and Foster. The paper concludes that social realism in the measurement of deprivation is often compromised by mainstream approaches to economic theorizing in which both heterogeneity and group-related externalities are generally de-emphasized.