( l ] )

GiventhemultitudeofpairsofvectorsxandyinDwhichstillcannotbe ranked,theprimarypurposeofanysuchpreorderingisnottherankinga;;such(since thisisoftenaratherdisappointingexercise),butrathertoprovideabenchmarktest forvariousproceduresthataffectinequality,liketaxationintheca"eofincomeinequality.Givenanysuchpreordering,iti"bothsensibleandrelevanttoaskwhether sometaxfunctionswillalways(i.e.,irrec;peetiveofthepretaxincomevectorx)rNluce inequality.