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 that venture. Looking towards econometric applications, it illustrates that a framework h la Malinvaud (i. e. based on the theory of temporary equilibrium with rationing) provides the means of improving macro- econometric modelling. There has been so far a wide and pervasive fear that, despite its analytical and theoretical usefulness, the quantity rationing approach would be much too complex to be successfully implemented into econometric models. The research the interested reader will discover in the subsequent pages should convince him that the difficulty faced by econometricians is essentially (I am tempted to say merely) one of developing an adequate methodology; it should thus disappear once is made the initial research investment. The empirical results presented towards the end of the book, though prelim- inary, already suggests that the effort is rewarding and should be continued. My debts are many.