Exploring the Geography of Routine Activity Theory: A Spatio-Temporal Test Using Street Robbery

Abstract

Many social phenomena have a spatio-temporal dimension and involve dynamic decisions made by individuals. Investigations focusing on the spatio-temporal dimensions of human behavior have received a great deal of theoretical attention; however, empirical testing of these theories has been handicapped by a lack of micro-level data and modeling tools that can capture the dynamic interactions of individuals and the context in which they occur. This research presents a methodology for evaluating theory through the implementation of a simulation model; the assumptions of the theory are operationalized in a model, a series of experiments are run, and the outcomes are analyzed to discover if they match what the theory would predict. Specifically, the concepts of routine activity theory (RAT) (Cohen and Felson, 1979) are formalized in a computational laboratory representing Seattle, Washington. The computational environment for implementation, Agent Analyst, merges agent-based modeling (ABM) software with geographic information systems (GIS). A strategy for developing activity spaces is implemented and demonstrates how agents can move along existing street networks, and land use patterns can be used to create representational activity spaces. Three versions of a model of street robbery are developed; each version implements a different level of constraints on agent's routine activities. In one version (Simple), individuals are either at home or not at home. In another, individuals follow a temporal schedule (Temporal). Last, individual's schedules are both temporally and spatially constrained (Activity Space). A series of experiments are conducted which compare the incidence and spatial pattern of street robbery events from each version. The results of the experiments provide strong evidence of the important role routine activities play in street robbery events. The addition of temporal and spatio-temporal schedule constraints reduces the incidence and changes the pattern of street robberies. Support for routine activity theory's premise, as time spent away from home increases street robbery will increase, is found in the Simple and Temporal, but not the Activity Space version of the model.