Monday, Dec 9
Sharon Kardia: Genomics in the Health & Retirement Study
Brown, Daniel, and Derek T. Robinson. 2006. "Effects of heterogeneity in residential preferences on an agent-based model of urban sprawl." Ecology and Society, 11 (1).
The ability of agent-based models (ABMs) to represent heterogeneity in the characteristics and behaviors of actors enables analyses about the implications of this heterogeneity for system behavior. The importance of heterogeneity in the specification of ABMs, however, creates new demands for empirical support. An earlier analysis of a survey of residential preferences within southeastern Michigan revealed seven groups of residents with similar preferences on similar characteristics of location. In this paper, we present an ABM that represents the process of residential development within an urban system and run it for a hypothetical pattern of environmental variation. Residential locations are selected by residential agents, who evaluate locations on the basis of preference for nearness to urban services, including jobs, aesthetic quality of the landscape, and their similarity to their neighbors. We populate our ABM with a population of residential preferences drawn from the survey results in five different ways: ( 1) preferences drawn at random; ( 2) equal preferences based on the mean from the entire survey sample; ( 3) preferences drawn from a single distribution, whose mean and standard deviation are derived from the survey sample; ( 4) equal preferences within each of seven groups, based on the group means; and ( 5) preferences drawn from distributions for each of seven groups, defined by group means and standard deviations. Model sensitivity analysis, based on multiple runs of our model under each case, revealed that adding heterogeneity to agents has a significant effect on model outcomes, measured by aggregate patterns of development sprawl and clustering.