Soft planning in macro-regions and megaregions : creating toothless spatial imaginaries or new forces for change?

Both planning practice and research increasingly acknowledge the existence of new scales and governance arrangements alongside and between statutory planning systems. Examples of new scales of non-statutory planning are large-scale megaregions and macro-regions. Drawing on examples from North America and Europe (Southern California and the Danube Region respectively), this article examines how new processes of cooperation at this scale can influence other statutory levels of decision-making on spatial development. The analysis of spatial delineations, discourses, actors, rules and resources associated with megaregions and macro-regions suggests that this type of ‘soft planning’ can foster territorial integration when a perception exists that there are joint gains to be made, when informal rules are negotiated in context-specific and bottom-up processes, when soft spaces are used as arenas of deliberation to renegotiate shared agendas, and when actors succeed in ensuring the anchorage of informal cooperation in other arenas.