Toru Maruyama

This is the first monograph that discusses in detail the interactions between Fourier analysis and dynamic economic theories, in particular, business cycles. Many economic theories have analyzed cyclical behaviors of economic variables. In this book, the focus is on a couple of trials: (1) the Kaldor theory and (2) the Slutsky effect. The Kaldor theory tries to explain business fluctuations in terms of nonlinear, 2nd-order ordinary differential equations (ODEs). In order to explain periodic behaviors of a solution, the Hopf-bifurcation theorem frequently plays a key role. Slutsky's idea is to look at the periodic movement as an overlapping effect of random shocks. The Slutsky process is a weakly stationary process, the periodic (or almost periodic) behavior of which can be analyzed by the Bochner theorem. The goal of this book is to give a comprehensive and rigorous justification of these ideas. Therefore, the aim is first to give a complete theory that supports the Hopftheorem and to prove the existence of periodic solutions of ODEs; and second to explain the mathematical structure of the Bochner theorem and its relation to periodic (or almost periodic) behaviors of weakly stationary processes. Although these two targets are the principal ones, a large number of results from Fourier analysis must be prepared in order to reach these goals. The basic concepts and results from classical as well as generalized Fourier analysis are provided in a systematic way. Prospective readers are assumed to have sufficient knowledge of real, complex analysis. However, necessary economic concepts are explained in the text, making this book accessible even to readers without a background in economics.

The role of asymmetric information in allocation of resources, together with the associated information-revelation process, has long been a central focus of economic research. While the bulk of the literature addresses these is­ sues within the framework of principal-agent relationship, which essentially reduces the problem to the sole principal's (the sole Stackelberg leader's) optimization problem subject to the agents' (the Stackelberg followers') re­ sponses, there are recent attempts to extend analysis to other economic setups characterized by different relationships among decision-makers. A notable strand of such attempts is the core analysis of incomplete in­ formation. Here, there is no Stackelberg-type relationship, and more impor­ tantly the players can talk to each other for coordinated choice of strategies. See, e.g., Wilson (1978) for a pioneering work; Yannelis (1991) for formula­ tion of feasibility of a strategy as its measurability; Ichiishi and Idzik (1996) for introduction of Bayesian incentive-compatibility to this strand; Ichiishi, Idzik and Zhao (1994) for information revelation (that is, endogenous deter­ mination of updated information structures); Ichiishi and Radner (1997) and Ichiishi and Sertel (1998) for studies of a specific model of Chandler's firm in multidivisional form for sharper results; and Vohra (1999) for a recent work. It is a common postulate in these works that every player takes part in design of a mechanism and also in execution of the signed contract.

A lot of economic problems can be formulated as constrained optimizations and equilibration of their solutions. Various mathematical theories have been supplying economists with indispensable machineries for these problems arising in economic theory. Conversely, mathematicians have been stimulated by various mathematical difficulties raised by economic theories. The series is designed to bring together those mathematicians who are seriously interested in getting new challenging stimuli from economic theories with those economists who seek effective mathematical tools for their researchers. The editorial board of this series comprises the following prominent economists and mathematicians: Managing Editors: S. Kusuoka (Univ. Tokyo), T. Maruyama (Keio Univ.); Editors: R. Anderson (U. C. Berkeley), C. Castaing (Univ. Montpellier), F. H. Clarke (Univ. Lyon I), G. Debreu (U. C. Berkeley), E. Dierker (Univ. Vienna), D. Duffie (Stanford Univ.), L. C. Evans (U. C. Berkeley), T. Fujimoto (Okayama Univ.), J.-M. Grandmont (CREST-CNRS), N. Hirano (Yokohama National Univ.), L. Hurwicz (Univ. of Minnesota), T. Ichiishi (Ohio State Univ.), A. Ioffe (Israel Institute of Technology), S. Iwamoto (Kyushu Univ.), K. Kamiya (Univ. Tokyo), K. Kawamata (Keio Univ.), N. Kikuchi (Keio Univ.), H. Matano (Univ. Tokyo), K. Nishimura (Kyoto Univ.), M. K. Richter (Univ. Minnesota), Y. Takahashi (Kyoto Univ.), M. Valadier (Univ. Montpellier II), M. Yano (Keio Univ).

A lot of economic problems can formulated as constrained optimizations and equilibration of their solutions. Various mathematical theories have been supplying economists with indispensable machineries for these problems arising in economic theory. Conversely, mathematicians have been stimulated by various mathematical difficulties raised by economic theories. The series is designed to bring together those mathematicians who were seriously interested in getting new challenging stimuli from economic theories with those economists who are seeking for effective mathematical tools for their researchers.

The role of asymmetric information in allocation of resources, together with the associated information-revelation process, has long been a central focus of economic research. While the bulk of the literature addresses these is­ sues within the framework of principal-agent relationship, which essentially reduces the problem to the sole principal's (the sole Stackelberg leader's) optimization problem subject to the agents' (the Stackelberg followers') re­ sponses, there are recent attempts to extend analysis to other economic setups characterized by different relationships among decision-makers. A notable strand of such attempts is the core analysis of incomplete in­ formation. Here, there is no Stackelberg-type relationship, and more impor­ tantly the players can talk to each other for coordinated choice of strategies. See, e.g., Wilson (1978) for a pioneering work; Yannelis (1991) for formula­ tion of feasibility of a strategy as its measurability; Ichiishi and Idzik (1996) for introduction of Bayesian incentive-compatibility to this strand; Ichiishi, Idzik and Zhao (1994) for information revelation (that is, endogenous deter­ mination of updated information structures); Ichiishi and Radner (1997) and Ichiishi and Sertel (1998) for studies of a specific model of Chandler's firm in multidivisional form for sharper results; and Vohra (1999) for a recent work. It is a common postulate in these works that every player takes part in design of a mechanism and also in execution of the signed contract.