1.1. Scope of the Book This book is a contribution to the area of "dynamic models of the firm". The motivation for this kind of research is the following: Empirical studies (e.g. Albach (1976)) have shown that the development of the firm over time can be divided into different stages. such as growth. stationarity and contraction. In order to understand and evaluate these stages in a proper way. it is important to develop a suitable theoretical framework. To that end. economists have applied dynamic mathematical techniques. such as optimal control theory. calculus of variations and dynamic programming to design and analyse dynamic models of the firm. In this way. the economic theory of the firm is extended to a dynamic context. Within the field of the dynamics of the firm this book - develops a general investment decision rule. based on the concept "net present value of marginal investment". which is applicable in deterministic dynamic models of the firm; - studies the influence of adjustment costs of investment on optimal dynamic firm behavior; - extends the stochastic dynamic theory of the firm by connecting it with a dynamic version of the Capital Asset Pricing Model. Before elaborating on "the dynamics of the firm". we first review the subject of net present value in the classical analysis.

Approaches to project scheduling under resource constraints are discussed in this book. After an overview of different models, it deals with exact and heuristic scheduling algorithms. The focus is on the development of new algorithms. Computational experiments demonstrate the efficiency of the new heuristics. Finally, it is shown how the models and methods discussed here can be applied to projects in research and development as well as market research.

This book is a slightly revised version of my doctoral thesis which I wrote during my time as an assistant at the Faculty of Economics of the University of Magdeburg. I am grateful that I had the opportunity to write my the sis in the stimulating atmosphere of this young and lively faculty. lowe a great amount of gratitude to my supervisor Prof. G. Schwodiauer who con stantly encouraged my work and helped to improve it in many discussions. I also would like to thank Prof. K-H. Paque and Prof. P. Flaschel who, as members of my doctoral committee, commented on various details of this study in a very constructive manner. At various stages of my work I received helpful comments from many colleagues of mine, in particular T. Konig and A. Wohrmann. However, it goes without saying that I retain full responsi bility for all remaining errors. Contents Introduction 1 I Money, inflation, and capital formation in the long run: general remarks 5 1 Summary of the literature: theoretical aspects 7 2 Summary of the literature: empirical aspects 19 3 Further reflections on money 29 II Money, inflation, and capital formation: the perspective of overlapping generations models 43 4 The Diamond model with money as single outside asset 45 4. 1 The model. . . . . . . . 46 4. 2 Equilibrium conditions. 51 4. 3 Policy effects 58 4. 4 Discussion. 61 4. 5 Appendix . 63 5 Variation 1: Imperfect credit markets and asymmetric information 65 5. 1 The model. . . . . . . .

and should therefore constitute a part of every area of economic 3 theory. The spectrum covered by information economics today ranges from Stigler's search theory4 to industrial economics, including oligopoly theory, innovation, as well as research and develop 5 ment. However, the area information economics is most closely connected with is the theory of optimal contracts, mainly ana 6 lyzed in principal-agent models. Contract theory deals primar ily with the question of how optimal arrangements (contracts) for the purchase and sale of commodities and services between two or more agents should be structured. In these models, it is often assumed that the parties to the contract are informed differently or asymmetrically about relevant variables (e. g. the health of one party in the case of insurance contracts, or the effort in relation to employment contracts). As a result of this asymmetric in formation, phenomena such as moral hazard, adverse selection, signaling, and screening may arise. Frequently, results from con tract theory are referred to when making statements about the effects of asymmetric information on an economy. Models of this kind are often used to explain phenomena such as fixed wages or unemployment, among others. 7 However, such conclusions must be treated with caution for two reasons. In the first place, in these models, a contract (explicit or implicit) is determined by the solution of an optimization prob lem.

This book presents recent developments in the field of ill-posed variational problems and variational inequalities, covering a large range of theoretical, numerical and practical aspects. The main topics are: - Regularization techniques for equilibrium and fixed point problems, variational inequalities and complementary problems, - Links between approximation, penalization and regularization, - Bundle methods, nonsmooth optimization and regularization, - Error Bounds for regularized optimization problems.

In the last decade highly innovatory developments have taken place in theoretical economics. The new focus of interest seems to be twofold: Firstly, nonlinear models for dynamic processes of the economy are constructed to extend the scope of linear models for tlle stationary euqilibrium state; and secondly a new approach is made to solve the everlasting problem of the relation between micro-and macro-economics. The interdisciplinary field of synergetics is deeply involved in this evolution. The author has made a remarkable contribution to both foci: His application of synergetic concepts to the theory of business cycles combines a partial solution of the micro-macro-problem, namely the modelling of the macro-economic effect of the decisions of investors, producers and consumers, with the natural introduction of nonlinearities. The arising new business cycle theory can on the one side be validated by empirical evidence and on the other hand the typical behavior of nonlinear dynamic systems including the transition to deterministic chaos can be clearly demonstrated. The hope is justified that the model presented in this book is a fw·ther important step in reaching a new level of the quantitative comprehension of dynamic phenomena in the economy. Stuttgart, June 1991 Prof. Dr. Wolfgang Weidlich Foreword It is the author's objective to explain macroeconomic processes on the basis of micro economic decision-making behaviour. In order to achieve this goal, the concept of synergetics is presented as a method of describing dynamic phenomena in multi-com ponent systems with cooperative interactions between their elements.

Inventory changes constitute in all countries a small fraction of the Gross National Product but also a major source or an indicator of cyclical fluctuations. In this volume both possible ways of propagation are investigated by examining in the first part what macroeconomists have learned and still have to learn about inventories in the light of statistical definitions and problems. In the second part, the role of monetary shocks in propagating business cycles is considered through liquidity effects and in relation to inventory adjustment. A possible linkage between inventory and labor market is shown. Finally, new evidence and theoretical insights are provided on the linear-quadratic inventory model and its ability to discriminate econometrically among competing firm behavior.