Spatial interactions in agent-based modeling

Agent Based Modeling (ABM) has become a widespread approach to model complex interactions. In this chapter after briefly summarizing some features of ABM the different approaches in modeling spatial interactions are discussed. It is stressed that agents can interact either indirectly through a shared environment and/or directly with each other. In such an approach, higher-order variables such as commodity prices, population dynamics or even institutions, are not exogenously specified but instead are seen as the results of interactions. It is highlighted in the chapter that the understanding of patterns emerging from such spatial interaction between agents is a key problem as much as their description through analytical or simulation means. The chapter reviews different approaches for modeling agents' behavior, taking into account either explicit spatial (lattice based) structures or networks. Some emphasis is placed on recent ABM as applied to the description of the dynamics of the geographical distribution of economic activities, - out of equilibrium. The Eurace@Unibi Model, an agent-based macroeconomic model with spatial structure, is used to illustrate the potential of such an approach for spatial policy analysis.Comment: 26 pages, 5 figures, 105 references; a chapter prepared for the book "Complexity and Geographical Economics - Topics and Tools", P. Commendatore, S.S. Kayam and I. Kubin, Eds. (Springer, in press, 2014

A theory of the city as object: or, how spatial laws mediate the social construction of urban space

A series of recent papers (Hillier et al 1993, Hillier 1996b, Hillier 2000) have outlined a generic process by which spatial configurations, through their effect on movement, first shape, and then are shaped by, land use patterns and densities. The aim of this paper is to make the spatial dimension of this process more precise. The paper begins by examining a large number of axial maps, and finds that although there are strong cultural variations in different regions of the world, there are also powerful invariants. The problem is to understand how both cultural variations and invariants can arise from the spatial processes that generate cities. The answer proposed is that socio-cultural factors generate the differences by imposing a certain local geometry on the local construction of settlement space, while micro-economic factors, coming more and more into play as the settlement expands, generate the invariants

Reviewing agent-based modelling of socio-ecosystems: a methodology for the analysis of climate change adaptation and sustainability

The integrated - environmental, economic and social - analysis of climate change calls for a paradigm shift as it is fundamentally a problem of complex, bottom-up and multi-agent human behaviour. There is a growing awareness that global environmental change dynamics and the related socio-economic implications involve a degree of complexity that requires an innovative modelling of combined social and ecological systems. Climate change policy can no longer be addressed separately from a broader context of adaptation and sustainability strategies. A vast body of literature on agent-based modelling (ABM) shows its potential to couple social and environmental models, to incorporate the influence of micro-level decision making in the system dynamics and to study the emergence of collective responses to policies. However, there are few publications which concretely apply this methodology to the study of climate change related issues. The analysis of the state of the art reported in this paper supports the idea that today ABM is an appropriate methodology for the bottom-up exploration of climate policies, especially because it can take into account adaptive behaviour and heterogeneity of the system's components.Review, Agent-Based Modelling, Socio-Ecosystems, Climate Change, Adaptation, Complexity.

Ambient Intelligence with Wireless Grid Enabled Applications: A Case Study of the Launch and First Use Experience of WeJay Social Radio in Education

Wireless grid and ambient intelligent (AmI) environments are characterized as supportive of collaboration, interaction, and sharing. The conceptual framework advanced for this study incorporated the constructs of innovation, creativity and context awareness while offering emergence theory -- emergent properties, structures, patterns and behaviors -- to frame and investigate a wireless grid enabled social radio application which was theorized to be potentially transformative and disruptive. The unintended consequences and unexpected possibilities of wireless grid and smart environments were also addressed. Using a single case study, drawing upon multiple data collection methods, this research investigated the deployment and use experience of WeJay, an application incubated through the Wireless Grids Innovation Testbed (WiGiT), from the perspective of beta trial participants. Guided by the broad research question -- Do wireless grid enabled applications, such as WeJay social radio, add to the potential for new and transformative outcomes for people, information and technology when deployed in an academic setting? -- this empirical study sought to: a) learn more about the launch experience of this first pre-standards wireless grid enabled application among WiGiT members and selected Syracuse University students and faculty; b) understand how this application was interpreted for use; c) determine whether novel and unexpected uses emerged; d) investigate whether wireless grid enabled environments fostered innovation and creativity; and e) elicit whether a conceptual relationship was emerging between wireless grid and AmI environments, focusing on context-awareness and ambient learning. While this early stage of diffusion and first user sample was a key limitation of the study it was also the core strength. Although challenged by the state of readiness of WeJay, study findings supported the propositions that WeJay fosters innovation and creativity; that novel and unexpected uses were generated; and that the theorized relationship between wireless grid applications and embedded awareness does exist. Recommendations for enhanced tool readiness were made and embedded smartness was found to be both desirable and beneficial. This research makes a contribution as a bridge study for future research while having theoretical and methodological implications for research and practice. Social, emotion/affect, and human-centered computing (HCC) dimensions emerged as rich areas for further research

From Social Simulation to Integrative System Design

As the recent financial crisis showed, today there is a strong need to gain "ecological perspective" of all relevant interactions in socio-economic-techno-environmental systems. For this, we suggested to set-up a network of Centers for integrative systems design, which shall be able to run all potentially relevant scenarios, identify causality chains, explore feedback and cascading effects for a number of model variants, and determine the reliability of their implications (given the validity of the underlying models). They will be able to detect possible negative side effect of policy decisions, before they occur. The Centers belonging to this network of Integrative Systems Design Centers would be focused on a particular field, but they would be part of an attempt to eventually cover all relevant areas of society and economy and integrate them within a "Living Earth Simulator". The results of all research activities of such Centers would be turned into informative input for political Decision Arenas. For example, Crisis Observatories (for financial instabilities, shortages of resources, environmental change, conflict, spreading of diseases, etc.) would be connected with such Decision Arenas for the purpose of visualization, in order to make complex interdependencies understandable to scientists, decision-makers, and the general public.Comment: 34 pages, Visioneer White Paper, see http://www.visioneer.ethz.c

The Hidden Fragility of Complex Systems -- Consequences of Change, Changing Consequences

Short-term survival and an exuberant plunge into building our future are generating a new kind of unintended consequence -- hidden fragility. This is a direct effect of the sophistication and structural complexity of the socio-technical systems humans create. It is inevitable. And so the challenge is, How much can we understand and predict about these systems and about the social dynamics that lead to their construction