After tackling the problems of production (2001-2002) and the economic aspects of consumption (2000-2001), the lecture then turned its attention to markets, successively reviewing labor and insurance markets (2002-2003), goods markets and oligopolistic competition (2003-2004) and finally financial markets (2004-2006). In 2007-2008, he shifted the focus from the elements of a system, the markets, to the system itself, the market, or, in the vocabulary of the profession, from partial equilibrium to general equilibrium. Attention was initially focused on the abstract Walrasian model of general equilibrium, as revitalized by modern economic theory. The lecture critically examined the merits and limitations of the model, with the seminars shedding light on its historical construction and opening up to related applications and issues.
Even if the Walrasian core of the subject may appear superficially outmoded, the general equilibrium problem remains at the heart of the construction of the discipline of economics. It permeates contemporary economic culture, from macroeconomic theory to growth theory to international trade theory. In fact, these topics were at the heart of the 2007-2008 program. If, as usual, the lecture was aimed at those wishing to take a general view of the subject, whether they were relatively far removed from it, or, being closer to it, sought to distance themselves from it, the field covered was broader than usual. International trade theory, growth theory and macroeconomic theory are three fields of specialization with a vast field of their own, and whose knowledge is based on widely differentiated traditions. However, beyond their common problem of general equilibrium in the broadest sense, there are justifications for a more unified treatment of these subjects : short-term macroeconomics, which I'll call macroeconomics tout court in the following, and long-term macroeconomics, i.e. growth theory, are subjects that are increasingly intertwined, in the sense that their analysis calls for models that are closer today than they were yesterday. In particular, the rapprochement between the analytical techniques used within these different subjects has been accentuated by the growing use of Dixit-Stiglitz hypotheses, which break with the fiction of the single aggregate good to introduce a variety of goods, at the cost of a symmetrization of the space of goods, which even if it is sometimes highly debatable or even caricatured, enriches the analysis. In fact, similar models have been introduced in the new theories of international trade, endogenous growth theory and the new Keynesian models, which today give a central role to oligopolistic competition.