The tasks of macroeconomics are to interpret observations on economic aggregates in terms of the motivations and constraints of economic agents and to predict the consequences of alternative hypothetical ways of administering government economic policy. General equilibrium models form a convenient context for analyzing such alternative government policies. In the past ten years, the strengths of general equilibrium models and the corresponding deficiencies of Keynesian and monetarist models of the 1960s have induced macroeconomists to begin applying general equilibrium models. This book describes some general equilibrium models that are dynamic, that have been built to help interpret time-series of observations of economic aggregates and to predict the consequences of alternative government interventions. The first part of the book describes dynamic programming, search theory, and real dynamic capital pricing models. Among the applications are stochastic optimal growth models, matching models, arbitrage pricing theories, and theories of interest rates, stock prices, and options. The remaining parts of the book are devoted to issues in monetary theory; currency-in-utility-function models, cash-in-advance models, Townsend turnpike models, and overlapping generations models are all used to study a set of common issues. By putting these models to work on concrete problems in exercises offered throughout the text, Thomas Sargent provides insights into the strengths and weaknesses of these models of money. An appendix on functional analysis shows the unity that underlies the mathematics used in disparate areas of rational expectations economics. This book on dynamic equilibrium macroeconomics is suitable for graduate-level courses; a companion book, Exercises in Dynamic Macroeconomic Theory, provides answers to the exercises and is also available from Harvard University Press.

Table of Contents:
Introduction References and Suggested Readings PART I REAL DYNAMIC MACROECONOMIC MODELS 1. Dynamic Programming A General Intertemporal Problem A Recursive Problem Bellman's Equations Nonstochastic Examples The Optimal Linear Regulator Problem Stochastic Control Problems Examples of Stochastic Control Problems The Stochastic Linear Optimal Regulator Problem Dynamic Programming and Lucas's Critique Dynamic Games and the Time Inconsistency Phenomenon Conclusions Exercises References and Suggested Readings 2. Search Nonnegative Random Variables Stigler's Model of Search Sequential Search for the Lowest Price Mean-Preserving Spreads Increases in Risk and the Reservation Price Intertemporal Job Search Waiting Times Firing Jovanovic's Matching Model Conclusions Exercises References and Suggested Readings 3. Asset Prices and Consumption Hall's Random Walk Theory of Consumption The Random Walk Theory of Stock Prices Lucas's Model of Asset Prices Mehra and Prescott's Finite-State Version of Lucas's Model Asset Pricing More Generally The Modigliani-Miller Theorem Government Debt and the Ricardian Proposition Remarks on Testing and Estimation Conclusions Exercises References and Suggested Readings PART II MONETARY ECONOMICS AND GOVERNMENT FINANCE 4. Currency in the Utility Function The Price of Inconvertible Government Currency in Lucas's Tree Model Issues and Models in Monetary Economics Government Debt in the Utility Function Government Currency in the Utility Function Seignorage and the Optimum Quantity of Currency A Neutrality Proposition Conclusions References and Suggested Readings 5. Cash-in-Advance Models A One-Country Model Fisher Equations Inflation-Indexed Government Debt Interactions of Monetary and Fiscal Policies Interest on Reserves A Two-Country Model Exchange Rate Indeterminacy Conclusions Exercises References and Suggested Readings 6. Credit and Currency with Long-Lived Agents The Physical Setup Optimal Allocations Competitive Equilibrium A Digression on the Balances of Trade and Payments The Ricardian Doctrine about Taxes and Government Debt The Model with Valued Currency and No Private Debt An Interventionist Optimal Monetary Equilibrium Townsend's "Turnpike" Interpretation Conclusions Exercises References and Suggested Readings 7. Credit and Currency with Overlapping Generations The Overlapping-Generations Model The Ricardian Doctrine about Taxes and Government Debt Again A Ricardian Proposition Currency, Bonds, and Open-Market Operations Computing Equilibria Interpretations as Currency Equilibria Optimality Four Examples on Inflation and Its Causes Seignorage and the Laffer Curve Dynamics of Seignorage Forced Saving International Exchange Rates Conclusions Exercises References and Suggested Readings 8. Government Finance in Stochastic Overlapping-Generations Models The Economy Some Examples A General Irrelevance Theorem Wallace's Modigliani-Miller Theorem for Open-Market Operations Chamley and Polemarchakis's Neutrality Theorem Interpretation as a Constant Fiscal Policy Indexed Government Bonds A Ricardian Proposition Further Irrelevance Theorems Conclusions Exercises References and Suggested Readings Appendix. Functional Analysis for Macroeconomics Metric Spaces and Operators First-Order Linear Difference Equations A Formula of Hansen and Sargent A Quadratic Optimization Problem in R A Discounted Quadratic Optimization Problem Predicting a Geometric Distributed Lead of a Stochastic Process Discounted Dynamic Programming A Search Problem Exercises References and Suggested Readings Index