From the reviews: "This volume is a collection of papers presented at the sixth annual Workshop on Economics with Heterogeneous Interacting Agents (WEHIA) that was held in Maastricht. ... A nice aspect of this ... book is that at several points the reader gets a direct comparison of substantially different approaches to develop models that deal with similar economic issues. ... Overall, this is a very interesting and useful book. The editors have been successful in attracting a strong group of active and original contributors ... ." (Herbert Dawid, Journal of Economic Behavior and Organization, June, 2005)