On an Implication of a Theorem Due to Gorman

This letter explores the robustness (in an approximating sense) of a class of demand systems which have been discussed by Gorman. This class is of fundamental interest because it is known to be the only class of demand systems which permits exact aggregation. We discuss the reasons which underlie the fact that one can not guarantee that an integrable member of the Gorman class can be found which will be as close as one desires to an arbitrary, integrable demand system