This series of lectures has its origins in the book entitled "Complex Economics: Individual and Collective Rationality" I published in 2010. The main objective is to argue that the current crisis has put into sharp relief the incapacity of our modern theoretical models and, in particular our macroeconomic models to provide an adequate explanation of the sudden and large changes that take place in the economy. The course will provide an account of how we have come to be locked into models which have been declared by former Governor Trichet of the European Central Bank, by Lord Turner, the Director of the Financial Services Authority in the U.K. and Governor Bernanke of the Federal Reserve Board to be useless in times of crisis. They have called for new approaches and this course will provide an opening to such approaches and will draw on the lessons to be learned from other disciplines, such as statistical physics, biology, and the neurosciences. The main theme, using various economic examples, will be to argue that the basic problem has been to treat the economy as if the aggregate behaved like a (representative) individual.

Séminaire dispensé par Alan Kirman (Université Aix-Marseille / EHESS).