Gravity and Spatial Interaction Models

Abstract

Spatial interaction is a broad term encompassing any movement over space that results from a human process. It includes journey-to-work, migration, information and commodity flows, student enrollments and conference attendance, the utilization of public and private facilities, and even the transmission of knowledge. Gravity models are the most widely used types of interaction models. They are mathematical formulations that are used to analyze and forecast spatial interaction patterns. The gravity model as a concept is of fundamental importance to modern scientific geography because it makes explicit and operational the idea of relative as opposed to absolute location. All things on the face of the earth AUTHORS ' NOTE: We would like to thank John M. Hollingsworth, Department of Geography, Indiana University, for his excellent cartographic work and patience in developing the diagrarns. 9 l0 can be located in absolute terms by longitude and latitude coordinates, and the absolute position of things can be related to each other by reference