[The sets of local demand functions which would generate either linear or nonlinear schedules in a heterogenous as well as homogeneous space economy are determined by iterative applications of the separation of variables technique for solving differential equations. Nonlinear delivered price schedules which reflect profit maximization objectives are thereby identifiable. In turn, these schedules can be distinguished from those which involve strictly predatory price behavior.]

[This paper develops an iterative procedure for estimating "specific" and "income" consumer unit scales in Engel curve analysis. The proposed procedure is essentially a modification of the Prais and Houthakker method and is illustrated by means of a numerical example based on the Indian National Sample Survey data.]