ANL/DIS/TM-59 Proceedings of the Workshop on Agent Simulation: Applications, Models, and Tools October 15-16, 1999 The University of Chicago Edited by Charles M. Macal and David Sallach Co-sponsored by Social Science Research Computation The University of Chicago and Decision and Information Sciences Division Argonne National Laboratory September 2000 ISBN 0-9679168-0-1 Available by request from Decision and Information Sciences Division Office Argonne National Laboratory 9700 South Cass Avenue Argonne, Illinois 60439-4832 Telephone: (630) 252-5464 Home page: http://www.dis.anl.gov/ Argonne National Laboratory Argonne National Laboratory, with facilities in the states of Illinois and Idaho, is owned by the United States Government, and operated by the University of Chicago under the provisions of a contract with the Department of Energy. Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor The University of Chicago, nor any of their employees or officers, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of document authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof, Argonne National Laboratory, or The University of Chicago. Reproduced from best available originals. CONTENTS Foreword ................................................................................................................................vii Acknowledgments ............................................................................................................... viii FRIDAY, OCTOBER 15, 1999 Agent-Based Social Science Models Why Agents? On the Varied Motivations for Agent Computing in the Social Sciences — Robert Axtell, The Brookings Institution ............................................................................. 3 Discussion — Fredrik Liljeros, University of Stockholm ........................................................................... 25 Political Agents Adaptive Models and Electoral Instability — Scott de Marchi, Duke University........................................................................................ 31 Agent-Based Modeling of Collective Identity: An Alternative Large-N Approach — Ian Lustick, University of Pennsylvania .............................................................................. 32 Discussion — Meredith Rolfe, University of Chicago ................................................................................ 34 Computational Models of Social and Economic Processes Thoughts on Diversity — Scott Page, University of Iowa............................................................................................. 39 The Efficiency of an Artificial Double Auction Stock Market with Neural Learning Agents — A Summary — Jing Yang, Bank of Canada ................................................................................................. 46 Modeling Organizations Using Agent-Based Simulations — M.V. Nagendra Prasad, Andersen Consulting LLP............................................................. 54 Discussion — David Sallach, University of Chicago ................................................................................. 67 iii Modeling Electrical Networks Learning with Simulation: Understanding the Strategic Implications of Deregulation and Competition in the Electricity Industry — Erik Larsen, City University of London............................................................................... 73 Modeling of Electric Power Markets by Adaptive Agents — Gerald Sheblé, Iowa State University.................................................................................. 96 Anticipatory Agents for the Deregulated Electric Power System — Lefteri Tsoukalas, Purdue University .................................................................................. 114 Discussion — Richard Cirillo, Argonne National Laboratory................................................................... 124 SATURDAY, OCTOBER 16, 1999 Agent Toolkits: Strategies and Tradeoffs Integrating Simulation Technologies with Swarm — Marcus Daniels, Swarm Development Group ..................................................................... 133 Ascape: An Agent-Based Modeling Framework in Java — Miles Parker, The Brookings Institution.............................................................................. 149 StarLogo: Building a Modeling Construction Kit for Kids — Andrew Begel, University of California, Berkeley............................................................... 175 Using a Rule-Based Programming Language to Model Rule-Based Behavior in Agent Simulation Models — Richard Gaylord, University of Illinois ............................................................................... 192 Discussion — Nicholson Collier, University of Chicago............................................................................ 196 Agent Methodologies and Model Validation GeoGraphic Smallworlds: Agent Models on Graphs — Catherine Dibble, University of California, Santa Barbara ............................................... 207 The Challenge of Validation and Docking — Richard Burton, Duke University ........................................................................................ 216 Discussion — Michael North, Argonne National Laboratory.................................................................... 222 iv The Agent Research Horizon Agents Plus: New Directions in Modeling Social and Organizational Systems — Kathleen Carley, Carnegie-Mellon University.................................................................... 229 Discussion — Robert Axtell, The Brookings Institution ............................................................................. 250 Closing Panel Results and Prospects — Randal Picker, University of Chicago; Charles Macal, Argonne National Laboratory; John Padgett, University of Chicago .................................................... 257 Discussion — Workshop Participants......................................................................................................... 263 List of Attendees ..................................................................................................... 269 v vi Foreword Agent simulation is a new approach to the study of social, economic, and physical systems. Following the publication of Thomas Schelling’s groundbreaking book, Micromotives and Macrobehavior (W.W. Norton, 1978), many scholars have made pivotal contributions that demonstrate the potential of complex, adaptive models for representing large-scale and emergent social processes. While many important effects have been demonstrated, this approach to studying complex systems is not yet a fully realized methodology. This workshop addressed several questions related to this new field of inquiry. • What has been accomplished so far? • In what areas does agent research have the potential to contribute? • What kind of information can agent models yield, and how should it be interpreted and used? • What constitutes validation of an agent model, and, in particular, what permutations and scaling of validation are needed as models become more complex? • What are the strengths and limitations of available agent toolkits, and what features are proposed — and needed — in the next generation of tools? • What is the research horizon? In addition to presentations and discussions on these larger issues, the workshop included presentations on specific applications in computational economics and agent models of electrical networks. The workshop was intended to provide a meeting ground for a stimulating exchange of diverse views. Indeed, a topic reiterated throughout the workshop was the importance of continued conversation between experts concerned with the content, theories, and conclusions of individual subject domains and experts concerned with advancing the art and science of simulation. From such conversations there will surely arise many unexpected and fruitful applications of the concepts and tools of complex adaptive systems. The proceedings are presented in that spirit. David Sallach Director, Social Science Research Computation The University of Chicago Thomas Wolsko Director, Decision and Information Sciences Division Argonne National Laboratory vii Acknowledgments Victor Lofgreen coordinated the logistics and managed the audiotaping of the workshop. Mika Robinson and Lisa Reyes also helped with logistics. Kathy Ruffatto handled registration and administration, and Bob Baker managed the workshop web site. Jane Andrew assembled and copyedited the proceedings, including presentations, abstracts, papers, and discussions, with help from Curt A. Strating and others from Alanwood Enterprises, Inc., for transcription of the discussions and Judith Robson for much of the word processing. ORGANIZING COMMITTEE David Sallach, University of Chicago (co-chair) Thomas Wolsko, Argonne National Laboratory