Research in trade relationships and hinterland analysis has shown that rural trade centers do not exist in isolation, but exhibit an interdependence with other rural and urban places. The purpose of this study is to examine relationships among trade centers by measuring their potential for growth.
The construct selected for growth analysis examines rural trade center population changes in relation to the size of rural trade centers, distance from urban centers, and the size of neighboring trade centers, both urban and rural. Trade centers having populations greater than 2,500 in 1970, were defined as urban. All trade centers considered were located within the politically defined boundaries of the State of North Dakota.
Detailed examinations of rural trade center relationships were made with respect to urban centers, and regional urban centers. The Fargo-Moorhead urbanized area located in Cass County was used as a case study. Urban centers were differentiated by size—2,500 to 5,000 (Category I) and 5,000 and over (Category II). Regional center population size was 10,000 and over. Population change of rural trade centers was selected as a measurement indicator. A positive population change from 1960 to 1970 was assumed to be indicative of a potential for future population growth and a symbiotic relationship. A negative population change was assumed to be indicative of a lack of growth potential and a competitive relationship.
The hypothesis selected for testing assumed rural trade centers to be at a disadvantage when located within 20 miles of urban centers. Underlying this assumption is the postulate that rural trade centers are integrated elements of a hierarchial system and function in association with urban centers. The methodology utilized tabular analysis to identify the relationships and correlation coefficients to measure the degree of association. Results of the tabular and statistical analyses were supplemented with field observations concerning the factors related to population change.
The results indicated weak associations between population change and distance to urban centers. It was found that Category I urban centers compete with rural trade centers. Also, a stronger association exists between growth of rural centers and distance to Category II and regional urban centers. Symbiotic relationships are most strongly developed in Cass County, however, growth patterns cannot be fully explained by the relationship between rural trade centers and the City of Fargo.
The correlation between rural trade center population change and distance to other rural trade centers was positive. Lack of statistical significance, however, prevented statistical verification of a competitive relationship. The correlation between size of rural trade center and population change was .18 and significant. In comparison to correlations between population change and distance to urban centers, this indicated that size of a rural trade center is a more important variable associated with growth in an area where relationships between urban and rural trade centers are weakly developed