This book grew out of a 'Doctorat D'Etat' thesis presented at the
University of Dijon-Institut Mathematique Economiques (lME). It aims to
show that quantity rationing theory provides the means of improving
macroeconometric modelling in the study of struc- tural changes. The
empirical results presented in the last chapter (concerning Portuguese
economy) and in the last Appendix (con- cerning the French economy),
although preliminary, suggested that the effort is rewarding and should
be continued. My debts are many. An important part of the research work
was accomplished during my visit to the Institut National de la
Statistique et des Etudes Economiques (lNSEE, Paris), where I have
beneficted from stimulating discussions (particularly with P. Villa) and
infor- matical support. I have also received comments and suggestions
from R. Quandt, J.-J. Laffont, P. Kooiman and P.-Y. Henin. I am
specially indebted to P. Balestra for encouraging and valuable
discussions, particularly in the field of econometric methods. My thanks
go also to an anonymous referee. His constructive criticism and
suggestions resulted in a number of improvements to an earlier version
of this book. I cannot forget my friend A. Costa from BP A (Porto) who
has helped me in the preparation of this work. Last but not least, I
would like to thank my wife for her encouragement and patience
throughout these years. Of course, I am the only one responsible for any
remaining errors.