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Title: The use of mathematical models in urban planning : the case of shopping models
Author: Turner, R. P.
Awarding Body: University of Sussex
Current Institution: University of Sussex
Date of Award: 1981
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This thesis presents the results of an empirical study of variants of five shopping models (central place theory, and the gravity, entropy intervening opportunities, and Building Research Establishment models), calibrated to data for four towns, using a range of estimation procedures (least-squares, chi-squares, maximum-likelihood). Various forecast scenarios, the effects of variations in the data, and disaggregating shopping trips by mode were also considered. The breadth of the study enabled it to systematically identify the scale of relative uncertainties: the largest source of overall uncertainty arose through model choice, then choice of calibration statistic, and finally through variations in the data. The general uncertainty was of a substantial degree - similar in magnitude to the forecasts themselves - and would therefore have ramifications for any policies based on the forecasts (some welfare implications were considered). The methodological principle adopted demanded that genarisations should be made from relatively aggregate results, further investigated at disaggregated levels only when anomalies appear. Hence, rather than deal with turnovers of individual centres the study dealt with the turnovers of 'local' centres taken together, 'district' centres taken together, and the 'town centre' treated seperately. This approach enabled a consideration of how the models 'trade-off' centre attractiveness against trip deterrence. The conclusion was' drawn that the largest modelling uncertainty occurs for local centres. The thesis also questioned whether present models constructively add to our understanding of the processes underlying urban change, Qr'whether.they actually deflect attention away from such considerations. The conclusion drawn was that the state of the art is impoverished in two respects: current modelling techniques provide forecasts with a wide degree of uncertainty when used practically; and they have theoretical deficiencies which do not enable them to handle the practical problems encountered • In planning this contradiction may be concealed by posing results as if they were relatively certain.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Civil engineering