It is argued that the market-area structure within the typical model o
f an urban system does not conform satisfactorily to the pattern custo
marily observed, The market-area structure of the standard model of a
central place system is modified, by applying, in turn, two additional
frameworks: the economic law of market areas and the law of retail gr
avitation, It is demonstrated that each application results in a more
realistic pattern of market areas, while preserving the hierarchical s
tructure of the central place system, The strengths and weaknesses of
each approach are examined, and further aspects of both approaches are
then considered.