23 Exclusionary Decision Making in Tehran Metropolitan Region- Complexity, Self organization and Power of Action Seyed Abdolhadi Daneshpour a, * , Atefeh Soleimani Roudi b a Associate professor, Faculty of Architecture and Environmental design, Iran University of Science and Technology, Tehran, Iran. b Ph.D candidate, Faculty of Architecture and Environmental design, Iran University of Science and Technology, Tehran, Iran. Received: 21 May 2018 - Accepted: 25 July 2018 Abstract Viewing urban areas as webs of complex, interwoven networks, this article aims to analyze the decision-making process and its outcomes in Tehran metropolitan region. To do so, first the theoretical basis of complexity in urban life and its implications for planning have been reviewed. Using the main notion of power of action i.e. agency, and through creating the network of actors and their relations as defined by the planning system, a qualitative assessment has been carried out. Findings suggest that the concluded decision-making trends and their corresponding planning interventions are feeding the power conflicts between actors and have mainly turned the inherent capacity of self- organization to solve problems into a rather harmful occurrence through processes of exclusion, the most prominent of which are: partial involvement of the actors of the network and a disregard for their interactions, silo mentality and sectoral and fragmented decision making. All of this point out to the necessity of a move towards a form of decision making that is more facilitating, inclusive, fluid and bottom-up in every aspect. Keywords: Urban complexity; Self-organization; Decision making process; Power/agency; Tehran metropolitan region. 1. Introduction For years planners and governance authorities in the city of Tehran and Tehran metropolitan region have tried to make sense of the reasons that the provided plans are not realized or implemented accordingly, for example why informal and illegal settlements are formed and grown despite the planning’s efforts regarding housing and employment provision. The low rate of the realization of plans in this context is the problem that this article wants to study through these questions: - Using a complexity approach, what are the some of the main trends in decision making in terms of actors and their relations? - How these trends are linked with the realization of the decisions? This article argues that trying to find the answers within the framework of complexity can be beneficial in two ways: firstly in understanding why things happen the way they do and secondly to find out what direction should future efforts take. This article chooses notions of ‘power’ and ‘agency to act’ within networks along with self-organization, as part of the complexity theory and complex systems theory, to show that the divergence from the formal planning, often considered negative by planners and administration, can actually be explained as the residents’ efforts in trying to create a better situation for themselves. Within this perspective, it seems that these occurrences can generally be deemed positive because they are based on the needs of the residents, realized by them, and also because they are collective actions rooted in individual endeavors. But where does the conflict come about? Or in other words, in what way does planning frustrate the self-organizing process? In the following sections, first there would be a brief review of the concepts of complexity in urban context and the notion of self-organization and how they relate to creating power of actions for different actors. Then the existing processes in the context in terms of decision- making and planning are introduced and analyzed to show how the conflict between the actions of the people, planning and administrative bodies arises. The article goes on to explain how the observed trends in the region, dubbed in this article as processes of exclusions, affect the position and power of the actors within the network and provide the contextual conditions for the self-organization to have incompatible and conflicting outcomes or in other words the context’s role in translating the efforts of the population into even more perceived imbalance. 2. Complexity and Cities In recent decades and with the development of new technologies, global reorganization of relations and environmental risks, the urban areas have gone through fundamental changes resulting in a new outlook on the roles of location and periphery, definitions of space and place, mobility and other concepts. Complexity and its theories have tried to provide a framework for understanding the new dynamics and their chaotic nature and unpredictability. Cities are no longer perceived as geographical entities with distinct identities. Rather, the urban today has * Corresponding author Email address: Daneshpour@iust.ac.ir