Exploring the possibility-cone of urban development

It is well known that urban systems are complex and nonlinear and exhibit properties of multiple equilibria and path dependence. This makes model-based forecasting in a conventional sense impossible. In this paper we explore how to achieve a deeper understanding of path dependence by constructing a “possibility cone” an envelope that contains feasible possible futures for a given urban system; and then exploring the consequences of this analysis for planning. Following Wilson (forthcoming) we characterise the factors that shape this cone as “urban DNA”. In the planning context, we can then examine the idea of urban “genetic medicine” and ask the question: what interventions would be required to move an urban system into a new possibility cone? These ideas are explored using a stochastic version of the archetypal aggregate retail model using data for the South Yorkshire retail system. We produce a visual representation of the cone of development using a parallel coordinates plot to allow easier interpretation of the results.