Horizontal Equity and Progession when Equivalence Scales are not Constant.

Abstract

Household needs must be taken into account when designing an equitable income tax. If the equivalence scale is income dependent it is not transparent how to achieve equity. In this paper we explore the question of horizontal equity and the implications for progression (vertical equity), when the equivalence scale depends on income level. In particular an 'equal progression among equals' criterion is articulated and shown to be achievable along with horizontal equity under specified conditions.