Uncertainty Within Economic Models

Book excerpt: "Studying this work in real time taught me a lot, but seeing it laid out in conceptual, rather than chronological, order provides even clearer insights into the evolution of this provocative line of research. Hansen and Sargent are two of the best economists of our time, they are also among the most dedicated teachers in our profession. They have once again moved the research frontier, and with this book provide a roadmap for the rest of us to follow. This is a must-have for anyone interested in modeling uncertainty, ambiguity and robustness."Stanley E ZinWilliam R Berkley Professor of Economics and BusinessLeonard N Stern School of BusinessNew York UniversityWritten by Lars Peter Hansen (Nobel Laureate in Economics, 2013) and Thomas Sargent (Nobel Laureate in Economics, 2011), Uncertainty within Economic Models includes articles adapting and applying robust control theory to problems in economics and finance. This book extends rational expectations models by including agents who doubt their models and adopt precautionary decisions designed to protect themselves from adverse consequences of model misspecification. This behavior has consequences for what are ordinarily interpreted as market prices of risk, but big parts of which should actually be interpreted as market prices of model uncertainty. The chapters discuss ways of calibrating agents' fears of model misspecification in quantitative contexts.