Key challenges in agent-based modelling for geo-spatial simulation

Agent-based modelling (ABM) is fast becoming the dominant paradigm in social simulation due primarily to a worldview that suggests that complex systems emerge from the bottom-up, are highly decentralised, and are composed of a multitude of heterogeneous objects called agents. These agents act with some purpose and their interaction, usually through time and space, generates emergent order, often at higher levels than those at which such agents operate. ABM however raises as many challenges as it seeks to resolve. It is the purpose of this paper to catalogue these challenges and to illustrate them using three somewhat different agent-based models applied to city systems. The seven challenges we pose involve: the purpose for which the model is built, the extent to which the model is rooted in independent theory, the extent to which the model can be replicated, the ways the model might be verified, calibrated and validated, the way model dynamics are represented in terms of agent interactions, the extent to which the model is operational, and the way the model can be communicated and shared with others. Once catalogued, we then illustrate these challenges with a pedestrian model for emergency evacuation in central London, a hypothetical model of residential segregation tuned to London data which elaborates the standard Schelling (1971) model, and an agent-based residential location built according to spatial interactions principles, calibrated to trip data for Greater London. The ambiguities posed by this new style of modelling are drawn out as conclusions

USE OF SIMULATION IN PLANNING

Community/Rural/Urban Development, Research Methods/ Statistical Methods,

Articulating Principals, Agents and Institutions in the EU

Principal agent problems arise frequently in situations of interdependence. Europe, with its various arrangements, is replete with principal agent problems that are mediated by institutions at various levels. While issues of water and land can provide a convenient focus, the essential problem is a deeper one. Decision making in principal agent situations has traditionally been considered in only a limited way. Current agency approaches seek to orient the interests of agents to those of the principal. More generalised formulations experience difficulties in reconciling interests. This is apparent not only in two-party forms but even more so in three-part(y) ones. In n-party environments things may appear to become simpler as n increases, but the problem may remain. An innovative exploration of a principal-agent situation which uses object-based concepts and simulations is presented in this paper. Different patterns of agent commitment are seen when it is applied to a European context. Suitable reconceptualisation of agency theory appears to have wide implications and applications. Its further development will allow more adequate specification of agency situations with immediate implications for policy and practice not only in Europe but in nations and regions around the world.

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.

Redesigning work organizations and technologies: experiences from European projects

Currently distributed business process (re) design (resulting in components of business networks) basically relies on technical criteria. And that are the main purposes of most research projects supported by EC. Through the process of building a European Research Area, this means a strong influence in the national research programmes. However it is generally accepted that it should also take into account social criteria and aspects such as the quality of working life, or participation in decision processes. Those were some of the objectives of projects in de 80s decade, and framed some of the main concepts and scientific approaches to work organisation. The democratic participation of network and organisations members in the design process is a critical success factor. This is not accepted by everyone, but is based in sufficient case studies. Nevertheless, in order to achieve an optimization that can satisfying the requirements of agility of a network of enterprises, more complex design methods must be developed. Thus, the support to the collaborative design of distributed work in a network of enterprises, through a concurrent approaching business processes, work organisation and task content is a key factor to achieve such purposes. Increasing needs in terms of amounts of information, agility, and support for collaboration without time and space constrains, imposes the use of a computer-based model.business process; networks; decision processes; collaborative design;

Dynamic analysis of bankruptcy and economic waves

The procedures presented in this paper provide a dynamic apparatus of crediting the industrial operating systems with the assignment to avoid their correlated defaulting, to conserve general safety and soundness and improve its ability to serve as a source for sustainable growth for economy. The quality of operating firms at different periods is evaluated using the migration matrixes between some classes of default risk.credit risk ; economic growth ; regulation

A software architecture for mechanism-based social systems modelling in agent-based simulation models

This paper introduces the MBSSM (Mechanism-Based Social Systems Modelling) software architecture that is designed for expressing mechanisms of social theories with individual behaviour components in a unified way and implementing these mechanisms in an agent-based simulation model. The MBSSM architecture is based on a middle-range theory approach most recently expounded by analytical sociology and is designed in the object-oriented programming paradigm with Unified Modelling Language diagrams. This paper presents two worked examples of using the architecture for modelling individual behaviour mechanisms that give rise to the dynamics of population-level alcohol use: a single-theory model of norm theory and a multi-theory model that combines norm theory with role theory. The MBSSM architecture provides a computational environment within which theories based on social mechanisms can be represented, compared, and integrated. The architecture plays a fundamental enabling role within a wider simulation model-based framework of abductive reasoning in which families of theories are tested for their ability to explain concrete social phenomena