Validation of an Agent-based Model of Deregulated Electric Power Markets Charles M. Macal and Michael J. North Center for Complex Adaptive Agent Systems Simulation (CAS 2 ) Argonne National Laboratory macal@anl.gov Abstract EMCAS (Electricity Market Complex Adaptive System) is an agent-based simulation model of the electric power market designed to investigate market restructuring and deregulation and to understand the implications of a competitive power market on electricity prices, availability, and reliability. Model validation is an essential parts of the model development process if models to be accepted and used to support decision making. This paper describes the validation process for the EMCAS model. Motivation for this study was based on the need to establish credibility for the EMCAS model and its results for use in practical decision making. The validation process also is an initial attempt to establish a general and practical framework for agent-based model validation. Contact: Charles M. Macal Center for Complex Adaptive Agent Systems Simulation (CAS 2 ) Argonne National Laboratory macal@anl.gov Tel: 1-630-252-3767 Fax: 1-630-252-6073 Email: macal@anl.gov Key Words: model validation, agent-based modeling, deregulated electric power markets Acknowledgments: The authors would like to acknowledge the other members of the EMCAS development team consisting of Gale Boyd, Richard Cirillo, Guenter Conzelmann, Vladimir Koratorav, Prakash Thimmapuram, and Thomas Veselka of the Decision & Information Sciences Division, Argonne National Laboratory. Support: This work is sponsored by the U.S. Department of Energy under contract W- 31-109-ENG-38.