Estimating nodal attractions with exogenous spatial interaction and impedance data using the gravity model

Unlike the conventional calibration of a gravity model in which nodal attra ctions are treated exogenously, this study treats the attraction of a node as an endogenous composite indicator of many contributing factors associate d with the node and estimates the nodal attraction based upon exogenous spa tial interaction (flow) and impedance data. An algebraic method is develope d for the general N X N O-D matrix and applied to a hypothetical 5 X 5 O-D flow case. A theoretical discussion of utilizing regression to estimate the contributing factors of nodal attractions is also presented. JEL classific ation: R40, R10, C63.