Inequality of post-tax income among pre-tax equals is evaluated and aggregated to form a global index of horizontal inequity in the income tax. The vertical action of the tax is captured by its inequality effect on average between groups of pre-tax equals. Putting the two together, horizontal...

This paper makes a new attack on the old problem of measuring horizontal inequity in the income tax. Local measures of inequality of posttax income among pretax equals are proposed, which reflect alternative value judgments about the nature and magnitude of an inequity. These measures are...