Department of Agricultural and Resource Economics

In this paper, different models of vertical relationships between manufacturersand retailers in the supermarket industry are compared. Demand estimates areused to compute price-cost margins for retailers and manufacturers underdifferent supply models when wholesale prices are not observed. The purpose isto identify the set of margins compatible with the margins obtained from estimates of cost and to select the model most consistent with the data among non-nested competing models. The models considered are (1) a simple linear pricing model; (2) a vertically integrated model; and (3) a variety of alternative (strategic) supply scenarios that allow for collusion, non-linear pricing, and strategic behaviour with respect to private label products. Using data on yogurt sold in several stores in a large urban area of the U.S. the results imply that wholesale prices are close to marginal cost and that retailers have pricing power in the vertical chain. This is consistent with non-linear pricing by the manufacturers or high bargaining power of the retailers.

Diminishing marginal utility (DMU) is neither necessary nor sufficient for downward-sloping demand. Yet, upper-division undergraduate and beginning graduate students often presumeotherwise. This paper provides two simple counter-examples that can be used to help students understand that the Law of Demand does not depend on DMU. The examples are accompaniedwith the geometry and basic mathematics of the utility functions and the implied ordinary/Marshallian demands.

We complete the characterization of two Frisch demand systems first developed by Browning et al (1985), and show that that these systems (i) do not restrict intertemporal substitution; but (ii) imply momentary utility functions which are additively separable in consumption. These utility functions turn out to take the well-known exponential and Stone-Geary forms.