Building the integrated inequality database and the seven sins of inequality measurement in Sub-Saharan Africa

The favourable growth performance of SSA over the last twenty years (Figure 1) - emphatically referred to by some as ‘the SSA Renaissance’ or ‘Africa Rising’ - has been accompanied by a perceptible, but still modest decline in poverty, from 59 to 48 percent over 1993-2010, i.e. much less than that recorded in South Asia (Ferreira 2014). Such aggregate trend however conceals substantial cross country variations. How to explain then such differences in poverty reduction rates? The standard approach (Bourguignon 2003) shows that the percentage change in poverty rates can be decomposed in the percentage change in GDP per capita growth rates and the percentage changes in the Gini coefficient, plus a (generally small) residual.2 In this regard, it must be noted that in SSA the average GDP growth per capita oscillated in a narrow range, i.e. between 1.7 percent in non-resource rich countries and 2.6 percent in resource-rich ones. The reason why poverty declined at different rates is therefore to be found in the divergence of inequality trends experienced by the countries of the region. This paper as well as Cornia (2014) and the literature quoted therein argue in fact that over the last 20 years the Gini index of inequality rose in several countries but simultaneously fell in a similar number of them. A proper documentation of inequality trends in the region becomes therefore essential to explain the above mentioned differences in poverty reduction. This task however is hindered by the limited and at time conflicting inequality data in the region and by the lack of a comprehensive database of good-quality and consistent inequality statistics. This situation is even more penalizing when considering that over the last two decades policy formulation has become increasingly ‘evidenced-based’, i.e. based not only on ideological and doctrinal priors but also on the empirical evidence provided by a growing number of household budget surveys (HBS), demographic and health surveys,(This abstract was borrowed from another version of this item.)