Flat rate taxes and inequality measurement

Tax flattening exercises which include an increase in personal allowances have been pervasive over the past two decades. Such changes, which typically benefit both the poor and the rich, at the expense of the middle class, have complex redistributive effects which are not obviously ‘equalizing’ or ‘disequalizing’. We develop a systematic approach to comparing the relative inequality of flat rate tax schemes to conventional graduated rate taxes. We provide an illustrative example using 1993 U.S. taxfiler data.