"Is the business cycle obsolete?" This often cited title of a book edited by Bronfenbren ner with the implicit affirmation of the question reflected the attitude of mainstream macroeconomics in the Sixties regarding the empirical relevance of cyclic motions of an economy. The successful income policies, theoretically grounded in Keynesian macroec onomics, seemed to have eased or even abolished the fluctuations in West,ern economies which motivated studies of many classical and neoclassical economists for more than 100 years. The reasoning behind the conviction that business cycles would increasingly become irrelevant was rather simple: if an economy fluctuates for whatever reason, then it is almost always possible to neutralize these cyclic motions by means of anti-cyclic demand policies. From the 1950's until the mid-Sixties business cycle theory had often been consid ered either as an appendix to growth theory or as an academic exercise in dynamical economics. The common business cycle models were essentially multiplier-accelerator models whose sensitive dependence on parameter values (in order to be called busi ness cycle models) suggested a rather improbable occurrence of continuing oscillations. The obvious success in compensating business cycles in those days prevented intensive concern with the occurrence of cycles. Rather, business cycle theory turned into sta bilization theory which investigated theoretical possibilities of stabilizing a fluctuating economy. Many macroeconomic textbooks appeared in the Sixties which consequently identified business cycle theory with inquiries on the possibilities to stabilize economies 2 Introduction by means of active fiscal or monetary policies.

This is the most sophisticated and up-to-date econometric analysis of business cycles now available. Francis Diebold and Glenn Rudebusch have long been acknowledged as leading experts on business cycles. And here they present a highly integrative collection of their most important essays on the subject, along with a detailed introduction that draws together the book's principal themes and findings. Diebold and Rudebusch use the latest quantitative methods to address five principal questions about the measurement, modeling, and forecasting of business cycles. They ask whether business cycles have become more moderate in the postwar period, concluding that recessions have, in fact, been shorter and shallower. They consider whether economic expansions and contractions tend to die of "old age." Contrary to popular wisdom, they find little evidence that expansions become more fragile the longer they last, although they do find that contractions are increasingly likely to end as they age. The authors discuss the defining characteristics of business cycles, focusing on how economic variables move together and on the timing of the slow alternation between expansions and contractions. They explore the difficulties of distinguishing between long-term trends in the economy and cyclical fluctuations. And they examine how business cycles can be forecast, looking in particular at how to predict turning points in cycles, rather than merely the level of future economic activity. They show here that the index of leading economic indicators is a poor predictor of future economic activity, and consider what we can learn from other indicators, such as financial variables. Throughout, the authors make use of a variety of advanced econometric techniques, including nonparametric analysis, fractional integration, and regime-switching models. Business Cycles is crucial reading for policymakers, bankers, and business executives.

Economic growth and business cycles are two distinct, but closely related issues. Economic growth is one of the most demanding challenges for policy makers and economists all over the world. In industrial countries, significant demographic changes in the decades ahead will have a major impact. At the same time, the degree of interdependency between economic regions is increasing, posing a challenge for industrial as well as developing countries. Business cycles as a topic for economic research sometimes follow a cyclical pattern themselves. Especially after long and strong boom periods the business cycle is often said to be obsolete, replaced by a new kind of pattern, a 'new' economy or the like. The empirical problem for analysts of both growth and business cycles is that new developments are difficult to monitor in real time. Cyclical, structural and other patterns are overlapping, making it difficult to assess the nature of observations. The INFER Annual Conference 2003 on "Determinants of Growth and Business Cycles: Theory, Empirical Evidence and Policy Implications" which was held in September 2003 in Giessen, Germany, gave room for theoretical papers, empirical results and case studies, including vigorous policy statements as well as elaborate modelling with a focus on practical relevance. Most of the presented papers and one of the introductory lectures are included in this volume. Papers were presented in three sessions: Session I focused on the "Determinants of Growth". Session II was on "Business Cycles: Theory and Empirical Evidence". Session III covered "Convergence and Economic Development". Contributors to this volume come from two continents and eight countries, working in research institutes, universities, central banks and international organisations.