The Differential Approach to Demand Analysis and the Rotterdam Model

This paper presents the differential approach to applied demand analysis. The demand systems of this approach are general, having coefficients which are not necessarily constant. We consider the Rotterdam parameterization of differential demand systems and derive the absolute and relative price versions of the Rotterdam model, due to Theil (1965) and Barten (1966). We address estimation issues and point out that, unlike most parametric and semi-nonparametric demand systems, the Rotterdam model is econometrically regular.