Tests of Intraurban Central Place Theories
For many years, economists have been interested in the reasons for the clustering of firms within cities. Early attempts to address this question seemed to focus primarily on the supply side of the market and revolved around the concept of' agglomeration economies' (see Richardson (I 978, pp. 4I -2)). More recently, economists have sought an explanation for clustering of firms by addressing the demand side of the market. Most of this attention has been directed towards showing how search behaviour on the part of consumers can lead firms selling similar products to cluster (see Stahl (i982a, b); Stuart (I979) and Eaton and Lipsey (Ig79b)). While these comparison shopping models take us part of the way towards understanding the spatial distribution of retailing, they cannot explain why firms selling non-substitutes also cluster together in shopping centres and why shopping centres come in different sizes. The classic model that was designed to explain these observations was the one proposed by Christaller (1 966). He obtained a hierarchy of shopping centres (or central places in his terminology) wherein firms selling different goods locate together. His model inspired much empirical research into interurban and intraurban retail structures despite the fact that his model lacked a firm microeconomic foundation. An attempt to remedy some of the behavioural deficiencies of the Christaller model has recently been made by Eaton and Lipsey (i982). They wanted to show that a hierarchy of shopping centres could be derived from a model that allowed for multipurpose shopping on the part of consumers and profit maximising locational choice on the part of firms. The hierarchy that they derive has some characteristics in common with Christaller's, and some that are different, and their model also yields testable predictions and insights that Christaller's model cannot supply because of its weak behavioural base. In this paper, we wish to test the empirical implications of both the Eaton and Lipsey model and Christaller model using sequential shopping centre data from Edmonton, Alberta. In the next section, we conduct a brief tour through the Eaton and Lipsey and Christaller theories of central places, and argue that it is the existence of demand externalities in the Eaton and Lipsey theory that enhances its predictive power over that of Christaller's. In Section II, we discuss how shopping centres are defined in this study, and how our shopping centre data are classified. Tests for a hierarchy of shopping centres are conducted in Section III. In the next two sections, we examine predictions that are made by the Eaton and Lipsey