Headcount Poverty Comparisons

Abstract

The most elementary, and also the most widely employed, means of assessing the extent of poverty in any society is to obtain a simple headcount of the poor. The poor are those whose incomes fall short of a stipulated poverty line. The commonest measure of poverty is the headcount ratio, H, which is the proportion of the poor in the total population. An alternative, and far less routinely used headcount index, is the aggregate headcount, A, which is the total absolute number of the poor. A problem for the measurement of poverty – and one which is only rarely acknowledged by professional economists – is that the headcount ratio and the aggregate headcount can provide contrary poverty rankings. For example, if in some initial time period 30 persons in a population of 100 are poor, while in a later time period 40 persons in a population of 200 are poor, then the headcount ratio declines from 30 per cent to 20 per cent, whereas the aggregate headcount rises from 30 persons to 40 persons. This type of problem is often encountered. For example, using a poverty line of 2.15 Purchasing Power Parity dollars per person per day, the global headcount ratio has been estimated to have declined from 66.7 per cent in 1981 to 52.9 per cent in 1991, while over the same period, the global aggregate headcount has been estimated to have risen from 2,450 million to 2,735 million. (...)O mais elementar, e também o mais amplamente empregado, meio de avaliar a dimensão da pobreza