2011-2015: an illustration based on the decomposition of the Gini coefficient using the Shapley value approach

This paper aims at measuring and analyzing for the first time the evolution of inequality in the distribution of expenditures among households in Togo over 2011-2015 and according to the characteristics of household heads. The study is based on the two most recent surveys (QUIBB 2011 and QUIBB 2015) and the monetary well-being indicator used is total expenditure per adult equivalent. With regard to the decomposition of the Gini index through Shapley's approach, within-groups inequality is greater than between-groups inequality for both years with an increase of total within-areas and within-age inequalities. The decomposition of overall within-groups component shows that urban areas, male-headed families and the 31-50 age group are more contributory. The increase of this contribution is observed for urban areas, the 31-50 age group while we have a slight decrease concerning gender. These findings witness that in Togo, policy actions to reduce inequalities should first target the within-groups expenditure disparities by focusing on the most contributory groups, and also without neglecting the between-strata effects.