THE MEASUREMENT OF INCOME DISTRIBUTION DYNAMICS WHEN DEMOGRAPHICS ARE CORRELATED WITH INCOME

We show how to account for differentials in demographic variables, in particular mortality, when performing welfare comparisons over time. The idea is to apply various ways of "correcting" estimated income distribution measures for "sample selection" due to differential mortality. We distinguish the direct effect of mortality, i.e. individuals who die leave the population and no longer contribute to monetary welfare, from the indirect effect, i.e. the impact on survivors in the deceased's household who may experience a decrease or increase in monetary welfare. In the case of Indonesia, we show that the direct and indirect effects of mortality on income distribution have opposite signs, but are roughly the same in magnitude. Moreover, the effects of other demographic changes dominate the effects of mortality, whether direct or indirect. However, in the post-crisis period these demographic changes also explain a substantial part of the overall change in the distribution of income.