Poverty and Inclusive Growth in the Light of the Quintile Income Statistic

Abstract

It appears that the World Bank is planning to maintain and disseminate systematic information on a version of what Kaushik Basu (now a Vice-President of the World Bank) had some years ago advanced as the ‘quintile income statistic’. The quintile income—which we shall find convenient to refer to simply as Q—is just the average income of the poorest quintile (that is to say, poorest 20 per cent) of a population. The quintile income statistic is a very simple, but also very versatile, welfare indicator—one which can be employed to cast light, admittedly in a somewhat elementary way, on aspects of both income poverty and the ‘inclusiveness’ of growth. The World Bank aims to track, subject to the availability of data, country-specific performance with respect to the average income of the poorest 40 per cent of the population (rather than 20 per cent, as Basu had proposed in his original version of the statistic)