1. The Idea behind the workshop was that of calling attention to the necessity of studying long term tendencies In economic growth. We believe that actual growth processes In capitalistic economies are not smooth phenomena and also that the evolution of the economy Is characterized by long term fluctuations as well as by trade cycles. It Is now common place to argue that this point of view was revived after 1973 In consequence of the economic difficulties experienced by Industrialized countries while It has a much older origin as Its roots can be pushed back at least to the Great Depression of the 1930's. In preparing this workshop we selected two main approaches (as reflected In the title of this book) that have been proposed In the last ten years to deal with the causes of long term fluctuations, namely the ··technologlcal"' (or neo­ SchumpeterlanLapproach and the "'social"' approsch. What follows Is simply a rough characterization of the existing theoretical positions and It Is not meant to be an exhaustive one. The Interested reader will Immediately see that there are many differentiated positions by looking at the arguments contained In each contribution.