CLUSTERING OF SERVICES IN CENTRAL PLACES.

Within a tertiary system entrepreneurs frequently must choose between places that command the largest local tributary population and places that possess the most desirable collection of complementary service activities. When command of tributary population is chosen over functional complementarity, the central place system increasingly assumes the clustering of activities in centers of a Läsch-like system and diverges from those to be expected in a Christaller-like system. From 1960 to 1970 some activities in central Iowa were becoming more closely associated with other activities, but others were becoming more independent. Overall. there were more departures from Christallcr's conditional order of entry principle at the end of this ten-year period than at the beginning. Seven functions in southern Minnesota from 1930 through 1970 showed departures from an order of entry scale that could be explained in terms of tributary areas which were larger than average for activities in places which lacked complementary activities, and smaller than average for activities absent from places which had a full complement of supporting activities. [ABSTRACT FROM AUTHOR]