In this respect I should like to mention the contributions by Lars Hansen as well as by Lars Svensson and Noah Williams. Both, “robust control” or “distribution forecast targeting” methods are designed to deal with model uncertainty. A second, and often related topic, is our still very incomplete knowledge of how financial markets work and how they deal with the problem of limited information.
Several papers at this conference illustrate the role of collateral and the problems we are confronted with if this instrument is not available. Let me mention as one example the paper by Larry Christiano and his co authors.