In current planning debates, the term 'shrinking city' usually describes a densely populated urban area that has, on the one hand, faced a considerable population loss, and is, on the other hand, currently undergoing a profound economic transformation, with some symptoms of a structural crisis (Pallagst, 2008). According to Oswalt (2006), more than a quarter of the world's metropolises shrank in the 1990s and, notwithstanding ongoing urbanisation processes, this number will continue to increase. With growing interconnectedness both on a European and on a global scale, a significant emerging task for planning researchers is to facilitate a wide-ranging exchange on economic, social, and environmental developments. On an international scale, for instance, it is still not clear whether, or in which way, planning paradigms, planning systems, planning strategies and planning cultures are being adapted when faced with the dynamics of urban shrinkage.
Different institutional and cultural conditions have brought about spatial planning systems displaying basic features that are essentially comparable; however, these planning systems are not identical but are tailored to meet specific cultural, normative and spatial situations. Despite the growing demand for an international viewpoint in urban and regional planning discussion, 'planning cultures' is not (yet) an established research topic in the sphere of urban and regional development. However, the topic has recently seemed to be on the rise in planning debate. As demonstrated by papers and tracks at several recent congresses of the Association of European Schools of Planning (AESOP), a considerable informal discourse about planning cultures already exists. Nevertheless, there is - on a global scale - no clear definition of the topic (Fuerst, 2009).
The term 'planning cultures' is not new - it can be traced back to Selle's work about collaborative planning (Selle, 1999). Interest in the topic of planning cultures may also be fuelled by the so-called 'cultural turn in planning' (Soja, 1999; Knieling and Othengrafen, 2009b), emphasising the role of culture in spatial planning, and thus recognising the impact of culture on spatial planning's international comparative research component. In particular, the growing demand for comparative research projects in the framework established by the EU's Community Initiatives, such as INTERREG, makes clear that planning culture is a component which is deeply embedded in a nation's planning system and thus needs to be considered in any comparative spatial research (Fuerst, 2009).
In recent years, two major projects have investigated planning cultures further: MIT has been at the forefront of research in this respect with the publication of an edited volume (Sanyal, 2005). In this book, Comparative Planning Cultures, John Friedmann (2005), who has written extensively about the changing notions of planning, sets out basic claims for dealing with planning cultures in discourse and in teaching, while at the same time acknowledging plurality. The second notable research work is the EU-funded project CULTPLAN, which addresses planning cultures in the European realm, and takes the research work further in particular for discussing theoretical approaches, and suggesting a 'culturalised planning model' (see Knieling and Othengrafen, 2009a; Othengrafen, 2010). It thus becomes clear that planning cultures is a multilayered subject facing continuing changes, some of them induced by factors such as Europeanisation and internationalisation.
Current debates in urban and regional studies display a rising awareness that several cities in Europe and the US have to deal with challenges of long-term demographic and economic changes leading to urban shrinkage associated with housing vacancies, underused infrastructure and other negative impacts.1 The issues of shrinking cities have often been predominantly interpreted as effects of the 'hollowing out' processes of the urban centres, triggered by suburbanisation and urban sprawl. …