In his Mattioli Lectures, Nobel Laureate Professor Herbert A. Simon directs attention to the kinds of empirical research that are necessary for progress in microeconomics. He traces the development of neoclassical economic theory and its gradual retreat from empiricism to abstraction. He then discusses the importance of business firms to the economic system, and the need for a thoroughly empirical understanding of how organisations work and reach their decisions. Finally, he examines innovative approaches to empirical research, including experimental economics, observational methods for studying economic behaviour, and the kinds of simulation models that are needed to interpret decision process. A round-table discussion of these issues follows; the participants, in addition to Professor Simon, are Professors Claudio Dematte, Massimo Egidi, Richard M. Goodwin, Robert Marris, Aldo Montesano and Riccardo Viale.