Simulating shrinkage as shock? Insights from existing shrinkage models

Modellers and social scientists attempt to find better explanations of complex urban systems. Such explanations include development paths, underlying driving forces, and impacts of such systems but might also include shocks. So far, land-use research has predominantly focused on urban – means population and/or settlement – growth. However, a comparatively new challenge has arisen since urban shrinkage entered the research agenda of the land use science. Although the phenomenon of urban shrinkage has become increasingly widespread in Europe, the US and Japan, urban land use modelling has rarely addressed it neither in terms of process description and dynamics, nor in terms of being a consequence of the 1989/1990 political transition shock. Based on knowledge of social science research (Haase et al. 2012), we first identify processes related to urban shrinkage by using the concept of pattern-oriented modelling. Second, we assess the capacity and pros and cons of existing land-use modelling approaches (system dynamics, cellular automata and agent-based models) to integrate the processes and variables of shrinkage. Third, we discuss in detail examples of existing simulation models that already cover aspects of urban shrinkage. So doing, we include a discussion of urban shrinkage as a consequence of shock in the urban system.