Some Properties of Income Gap Ratio and Truncated GINI Coefficient

The income gap ratio and truncated Gini coefficients play an important role in the construction of poverty and affluence indices. In this paper we examine the question of determining the form of the income distributions based on the income gap ratio or truncated Gini coefficient for a given population and answer them in affirmative. We also discuss the behaviour of the Sen poverty index with respect to the head count ratio and the parameters of some selected income distribution models.