The bandwagon effect model of spatial interaction : an information-based model of population migration
Popoff, James Jonathan
This research introduces an alternative conceptual framework for the rational-economic spatial interaction model (SIM) that geographers and others have worked with for almost thirty years. SIMs use numerical interpolation to 'calibrate' a negative-exponential parameter on rational cost (friction of distance). The parameter allows researchers to infer characteristics of the population. An alternative interpretation is called the bandwagon effect (BWE) because it seeks an analogy with the tendency of crowds to attract more members. The BWE assumes that the raw quantity of information about a place supersedes rational cost in the mind of a spatial decision-maker (SDM). A surrogate for all possible information emanating from a place is the rate of out-migration observed there in units of the out-migration at the SDM's origin. The SIM is respecified with information in place of rational cost, and interpreted to mean that places that are losing fewer residents are more attractive. Two interregional migration datasets (Canada 1976-1981, and U.S.A. 1965-1970) are used to compare the methods. Information is found to be uncorrelated with distance in both data sets. The BWE is observed to substantially exceed the performance of the SIM with Canadian data, and to match it with U.S. data.