THE LAW OF RETAIL GRAVITATION - INSIGHTS FROM ANOTHER LAW

The law of retail gravitation (LRG) and the economic law of market are as (LMA) both seek to define the market-area boundary between two comp eting centres. Each law is reviewed and then characterized in terms of the principal dimensions of the market-area boundary. It is shown tha t under certain conditions the two laws correspond exactly, so that th e LMA is able to lend some economic support for the LRG. If, however, approximate correspondence between the laws is permitted, this support is considerably greater. The two laws are also viewed within the broa der framework of an hierarchically structured urban system. Exact corr espondence between the laws is again possible under particular circums tances, but the descriptive capacity of the LMA is greatly increased w hen approximation is allowed. Finally, consideration is given to the p ossibility of modifying the LMA in order to take account of the effect s of nonprice competition.