Decomposing Poverty Change: Deciphering Change in Total Population and Beyond

In the understanding of decomposing poverty change, the growth effect of mean income is replaced with the growth effect of total income and the impact of change in total population. These two, along with changes in inequality, form the three broader effects that can be computed in multiple ways depending upon the base period and the sequence of calculation. Changing the base does not alter the broader effects while specific attributions within each effect get interchanged. For a given base, there will be six possible sequences and we take an average of these to compute the three broad effects. Finally, poverty change on account of the three broad effects comprising growth of total income, change in inequality, and change in total population are shown as part of the within‐group effect while change in population shares, which is different from change in total population, is a between‐group effect. We provide empirical illustrations with data from India.