An economic agent-based model of coupled housing and land markets (CHALMS)

This paper describes a spatially disaggregated, economic agent-based model of urban land use, which is named for its innovative feature of coupled housing and land markets (CHALMS). The three types of agents—consumer, farmer and developer—all make decisions based on underlying economic principles, and heterogeneity of both individuals and the landscape is represented. CHALMS simulates the conversion of farmland to housing development over time, through the actions of the agents in the land and housing markets. Land and building structures in the housing bundle are treated explicitly, so the model can represent the effects of land and housing prices on housing density over time. We use CHALMS to simulate the dynamics of land-use changes as a representative suburban area grows. The presence of agent and landscape heterogeneity, stochastic processes, and path dependence require multiple model runs, and the expression of spatial dispersion of housing types, overall housing density, and land prices over time in terms of the most likely, or ‘average’, patterns. We find that CHALMS captures both the general tendency for diminishing population density at greater distances from the center city, and dispersed leapfrog patterns of development evident in most suburban areas of the US.

Research highlights
► Microeconomic decision-making is integrated into an agent-based framework.
► Heterogeneity in agent preferences and landscape features is represented.
► Coupled housing and land markets produces spatial patterns of development density.
► Agents’ price expectations capture spatially dependent price trends.
► Stylized facts and spatially explicit patterns from urban economics reproduced.