This book constitutes the thoroughly refereed postproceedings of the 9th International Workshop on Multi-Agent-based Simulation, MABS 2008, held in Estoril, Portugal, in May 2008. they present state-of-the-art research results in agent-based simulation and modeling. The papers are organized in topical sections on simulation of economic behaviour;

Simulation of Economic Behaviour.- Modeling Power Distance in Trade.- Intrusion of Agent-Based Social Simulation in Economic Theory.- Modelling and Simulation of Social Behaviour.- A Model for HIV Spread in a South African Village.- Understanding Collective Cognitive Convergence.- Dynamics of Agent Organizations: Application to Modeling Irregular Warfare.- Applications.- Using Simulation to Evaluate Data-Driven Agents.- Evaluation of Automated Guided Vehicle Systems for Container Terminals Using Multi Agent Based Simulation.- MASFMMS: Multi Agent Systems Framework for Malware Modeling and Simulation.- Techniques, Infrastructure and Technologies.- Towards a Formal Semantics of Event-Based Multi-agent Simulations.- A User Interface to Support Dialogue and Negotiation in Participatory Simulations.- Towards Agents for Policy Making.- Methods and Methodologies.- A Quantitative Method for Comparing Multi-Agent-Based Simulations in Feature Space.- Deepening the Demographic Mechanisms in a Data-Driven Social Simulation of Moral Values Evolution.- Cross-Disciplinary Views on Modelling Complex Systems.- Towards a New Approach in Social Simulations: Meta-language.

This book constitutes the thoroughly refereed postproceedings of the 9th International Workshop on Multi-Agent-based Simulation, MABS 2008, held in Estoril, Portugal, in May 2008. The 16 revised full papers presented have gone through two rounds of reviewing, selection, and improvement and were selected from 44 submissions; they present state-of-the-art research results in agent-based simulation and modeling. The papers are organized in topical sections on simulation of economic behaviour; modelling and simulation of social behaviou; applications; techniques, infrastructure and technologies as well as methods and methodologies.