'Some 25 years ago, Frank Hahn a leading economic theorist said, '... wildly complex systems need simulating ... while there will be work for the computer scientist, I very much doubt that economists will be able to establish general propositions in any but very special examples'. Economists have reacted by saying 'show us an alternative'. This book does just that. It provides the elements of an alternative computational approach in which aggregate phenomena such as crises do not appear from the blue, but emerge from the interaction between simple but heterogeneous agents.' Alan Kirman, University of Aix-Marseille III 'The authors conceive of economies as complex systems of heterogeneous interacting agents with bounded rationality and limited information, and they view agent-based modeling as a necessary tool for the exploration of such systems. In this book the authors provide a comprehensive introduction to agent-based modeling. Although macroeconomic applications are stressed, the coverage of topics such as rationality, behavior, expectations, and learning will be of value for many other applications as well. A particularly welcome aspect of the book is its attention to historical antecedents and its inclusion of chapters devoted to empirical validation and estimation issues.' Leigh Tesfatsion, Iowa State University