University of Illinois at Chicago Circle and Massachusetts Institute of Technology, respectively. The authors have received helpful comments from a large number of individuals in the course of this study. Particular thanks are expressed to Franco Modigliani. The rather heterodox views presented in this paper are to be ascribed solely to the authors, however; they alone bear responsibility. They express grateful appreciation to Nancy Davidheiser, Roy Henriksson, Geoffrey Ward, and Kwame Yeboah for their able research assistance.