A New Measure of Horizontal Equity

摘要

We have derived a measure of horizontal equity that allows for separate social preferences toward vertical and horizontal equity. To illustrate our measure, we have explored the change in horizontal inequality of the U.S. federal income tax, and examined a recent proposal to undo the "marriage penalty." Conditional on known values of preferences toward vertical and horizontal inequality, our work is a contribution to the positive theory of measurement. While it may make sense to relax the constraint that society's preferences toward the two types of inequality be identical, there is also little guidance as to the appropriate relative weight- ing, or how to determine individual reference groups. The exploration of the consequences of different attitudes toward horizontal and vertical inequality is an important subject of future inquiry.