Introducing his book "The Theory of UnemPloyment Reconsidered," Professor Malinvaud expressed several years ago his hope "to convey his] strong belief that the reconsideration is a major step in the development of our science." In view of the stimulating effect this approach has on economic research, it seems now that many economists do indeed share Malinvaud's belief and are ready to devote their time and their skill to ensure the realization of that progress. This book, grown out of a Ph. D. thesis presented at the Universit Catholique de Louvain, aims at contributing in its own way to...