| Including the poor |
|Part I. Concepts and measurements|
|2. Measuring poverty: Definitions and significance tests with application to Côte d'Ivoire|
Foster, Greer, and Thorbecke (1984) proposed a class of poverty measures that are additively decomposable. This class of measures is obtained if we substitute
in equation 2.2:
where a is a parameter to be specified. These measures satisfy Sen's monotonicity axiom if and only if a > 0 and Sen's transfer axiom if and only if a > 1. When a > 2, Pa also satisfies Kakwani's transfer sensitivity axiom.
Watts (1968) proposed a poverty measure that can be obtained by substituting q (z, x) = logz - logx:
Although this is an extremely simple poverty measure, it has all the important attributes: it satisfies Sen's monotonicity and transfer axioms and Kakwani's transfer sensitivity axiom.
Finally, we consider the Clark, Hemming, and Ulph (1981) poverty measure, which can be obtained by substituting
where b is a parameter to be specified. These measures clearly satisfy Sen's monotonicity axiom if and only if b > 0. Both the transfer and the transfer sensitivity axioms will be satisfied for all b < 1. Thus, b must lie in the range 0< b < 1.