Using a Hybrid Model for Investigating Residential Segregation: An Empirical and Simulation-based Study

Abstract

The impact of residential segregation on the dynamics of spatial, social and economic spheres of society is a topic of great interest in geography, sociology and economics. Residential segregation and its spatial separation effects have been acknowledged as having significant impacts on education, healthcare, business as well as social network and social/ urban structures. The complexity and multidimensional nature of the residential segregation phenomenon and the centrality of the individual based decision making process made this topic an ideal case for investigation using a micro/ individual based simulation modelling approach. An example of such an approach is agent‐based modelling (ABM) as theorised by Thomas Schelling. However, most Schelling‐type models are often too simple and small. This lack of sophistication and ‘small‐village’ syndrome remain though among the major weak points of existing models generally. More importantly, the lack of empirical support for informing and verification has long impeded the widespread acceptance of most simulation modelling approaches of this kind. Various individual based simulation modelling approaches to investigate residential segregation are reviewed. In particular, two simulation modelling approaches – agent‐based modelling (ABM) and microsimulation (MSM) – are compared with the aim of embracing a combined design approach that will also include key features of geosimulation models. For this reason a series of model prototypes are built initially to examine different aspects of a combined design approach, and with consideration of available census data (in aggregate format), the HAAMoS model is ultimately presented. It can simulate the entire population of the Auckland metropolitan area whilst dealing with up to four major ethnic groups each of which exhibit heterogeneous behaviours and have multi‐level preferences. It can also measure various dimensions of segregation, including local and spatially sensitive ones at different geographical scales. The implementation of these features is described. A descriptive statistical analysis of the modified data describes past and present patterns of residential location by ethnicity in the Auckland region area, which in turn are used as ‘benchmarks’ against the model’s outputs. Using specific scenarios, it is demonstrated that this relatively simple Schelling‐type model – informed by empirical data – has the potential to replicate plausible residential distribution patterns, even though the detailed representation of decision making behaviours are not available/ used. This demonstration confirms that the development of a potential ‘test‐bed’ consisting of an agent‐based model using census data for future modelling‐based research which can address residential and socio‐spatial segregation questions and similar theoretical issues in urban geography, sociology or economics would be feasible. The methodological approaches built and used in this research are among its important achievements. Further possible extensions of this research under different topics are also discussed.