Índices de pobreza y funciones de bienestar

In the article: "Indices de pobreza: una discusión metodológica" published in the previous number of this journal we presented three indices P1, P2 and P3. The first is based on the percentage of poor people below a fixed poverty line, the second ads a measure of the gap between the poverty line and the average income of the poor. While the third considers in addition the degree of inequality amongst the poor. This paper considers an ordering amongst distributions of income based on these three indices. The first turns out to be equivalent to welfare functions based simply on the supposition that utility rises with income. Indices based on P2 are equivalent to welfare functions which increase with any transfer from a richer to a poorer person that is with any progressive transfer. P3 is shown to introduce the additional element whereby welfare rises more the poorer the person receiving a given transfer.