We extend the set of full rank nominal and deflated income demand systems to rational demand systems of any rank and present a unifying expression for the indirect preferences of all full rank demand models.

Gorman's class of Engel curve demand models is extended to incomplete demand systems. The Gorman class of aggregable incomplete demand systems admits any transformation of deflated income. A maximum rank of three for the demand equations is a corollary of Slutsky symmetry. Models of incomplete...