Reviewed by
Andreas Koch
Department of Geography and Geology, University of Salzburg, Austria
In their book, Lai and Han suggest critically evaluating the significance of (urban) planning under increasingly complex circumstances, both in planning and in urban development. They therefore introduce theories and models that appear to be adequate and reliable in achieving this specialized task. Most prominently presented is the so called “garbage can model” which has been applied to situations involving organisational decisions. Furthermore, they take cellular automata (CA), agent-based modelling (ABM) and network analysis (NA) tools into account in order to yield a more comprehensive result on the meaning of planning.The book is structured into 14 chapters beginning with introductory remarks about the garbage can model, followed by the application of cellular automata and agent-based models in a spatial urban context, the rank size and power law rules, and ending with a synoptic merging of all methodologies with the goal of a simulation framework utilisable for stakeholders in the relevant fields.
A central problem in the book is that it is based on a fuzzy definition of planning – “the collection of information to minimize uncertainty” (based on Hopkins (2001)) – and this definition is applied to all planning situations, whether organisations, companies, households, or individuals, and urban planning. Moreover, Lai and Han exclusively refer to this single approach throughout the book and thus assume that this definition always applies regardless of any global or political differences. However, European planning philosophy, in itself diverse, is far from being similar to American or Chinese planning philosophies to which the authors mainly refer when discussing their methodological approaches. The differences between planning theories in fact affect the ways these theories are applied and translated into political agendas, societal practice, legal foundations, and cultural values. To illustrate, planning in China has a completely different political, scientific, and everyday life connotation in comparison to planning in the United States, Western, or Eastern Europe.
My personal understanding of Lai and Han’s definition of (urban) planning is thus more equated with a kind of metaphor. This epistemological perspective could serve as an advantage when trying to adequately comprehend their methodological claims. They advocate computer simulation, meaning ABM and CA in their understanding, and these approaches are coupled with other models and theories such as the garbage can model. This model, introduced in the 1970s by Cohen et al. (1972), tries to represent organisational decision behaviours in addition to complexity theory, game theory, rank size phenomena, and network analysis.
With all of these tools in the methodology box, a pronounced bottom-up approach of planning is utilised that is conclusively tied to the techniques chosen, but it is unsatisfactory as long as the complementary side of macro structures of planning is neglected. As a concrete example chapter 6 applies CA to simulate planning effects on urban development in an abstract way, but this approach may be seen as only one possibility among several to simulate decision processes between different stakeholders which affect urban development in one way or another. Apart from the issue of critically reducing the agents’ behaviour settings to either “cooperate” or “defect” in land development processes, it is also questionable whether solely referring to the local scale, which is the adjacent eight neighbour cells in a raster-based spatial representation, is sufficient when discussing the meaning of planning. Not least in this sense is the statement “the simulation can explain real world situations” (page 113) misleading. The problem here is a lack of theoretical and epistemological plurality.
With reference to urban segregation processes, social geography, for example, benefits from both bottom-up approaches (utilising, among others, Schelling-style ABM by taking individual decisions into account to explore emergence) and top-down approaches (such as rent-gap theory which stresses the meaning of housing markets and related institutions like real estate agencies, global networks of financial investments, and the varying influence of urban planning; see Smith (1987), Knox and Pinch (2014)). In other words, Lai and Han do not take preferences, desires and needs into consideration; these all seem to play no role in planning processes or in urban development. Equally problematic is that Lai and Han treat all agents the same way, leaving out any differences in power relations, already existing network relationships and subjective interests in planning goals.
In his foreword to the book, Michael Batty states: “This is not an easy book to read. It switches the focus from the comfortable, more conventional ways of planning based on communicative and learning processes dominated by diverse stakeholder interests, and from standard ideas about cities as complex systems which show emergence, fractality, and so on, to the ground between. This is difficult terrain and it forces the reader to think long and hard about the goals of planning and the way cities respond to these in terms of the way they evolve. In the last three chapters, they pull these ideas together, proposing a more generic framework for planning and design”. The intentions of the book are thus not clear and straightforward, which may not be a disadvantage in general, since sometimes ambiguity supports a self-critical thinking.
Although an inherent line of thought can be detected with the objective of connecting specific theories to specific models in order to link planning and urban development, the chapters are actually only loosely coupled, resulting in a large amount of redundancy when reading the book in a sequential order. This could be due to the fact that half of the 14 chapters were separately published in various journals over a rather long time span – the first chapter originating from 1998 and the most recent chapter (Chapter 12) from 2012. Thus the “and” in the title, signifying the link between the two core topics of “urban complexity” and “planning”, does not seem to be shown. My impression is that all chapters swing more or less arbitrarily between the core topics, except the last three chapters, where Lai and Han successfully and persuasively pull the various strands together into some kind of synopsis. If these last three chapters were the first three, then the entire idea behind the book (as assumed here) would be clearer, and the book would unfold as a kind of retrospective step-by-step research process in the respective fields.
A good argument for this perspective can be made in that all previously published chapters have not been revised for this publication; relevant literature from the past decade is largely missing, especially in respect to ABM, geography and planning. Though it is absolutely acceptable to refer to literature and approaches from the 1970’s to the 2000’s due to their continuing relevance today, it is at the same time vital to also refer to the basic literature of the last five to ten years when discussing a topic within a scientific context. In the fields of ABM and similar techniques, as well as planning theory, significant progress has been made in recent years (see Edmonds and Meyer (2013), Heppenstall et al. (2012), two publications mentioned here of the many) which could ultimately enrich the findings of Lai and Han instead of weaken them.
ReferencesEDMONDS B. and Meyer R. (eds.) (2013), Simulating Social Complexity. Springer, Dordrecht.
HEPPENSTALL, R., Crooks, A.T., See L.M. and Batty M. (eds.) (2012), Agent-Based Models of Geographical Systems. Springer, Dordrecht.
HOPKINS, L.D. (2001), Urban Development: The Logic of Making Plans. Island Press, London.
KNOX, P. and Pinch, S. (2014), Urban Social Geography. An Introduction. 6th edition, Routledge, London.
SMITH, N. (1987), Gentrification and the Rent Gap. Annals of the Association of American Geographers, vol. 77, no. 3, p. 462-465.
Return to Contents
of this issue