Poverty Measurement: the Critical Comparison Value.

The basic problem in poverty measurement is how to weigh the income of different groups. This is a normative problem on which people differ in opinion, and hence we should seek a way of dealing with the issue that takes into account this plurality. In the paper, we suggest an approach to poverty measurement which avoids incorporating any particular normative position on how to weigh the interests of various poor groups, but rather reports on changes in poverty by making explicit the link between various normative positions and ordinal conclusions in poverty measurement. Within this framework, by applying a generalized version of Decartes' Rule of Signs, we present results that should provide useful guidance in a poverty comparison.