Calibrating a Residential Location Model for Nineteenth-Century Philadelphia

The Disaggregated Residential Allocation Model (DRAM) is a modified Lowry derivative model which follows the Wilson entropy formulation. The model is a component of the Integrated Transportation and Land Use Package—ITLUP. As a part of ongoing work with DRAM, it has been calibrated for several US cities by use of conventional late twentieth-century data sets. Because of the work of the Philadelphia Social History Project a nineteenth-century data set for Philadelphia became available for use. This provided a unique opportunity to try calibrations of DRAM on this century-old data and thus attempt to validate the general structure of the model. The results of these calibrations suggest a rather high degree of descriptive validity and consistency with macro-behavioral theories of spatial allocation.