Economics: Beyond the Millennium contains articles by leading authorities in various fields of economic theory and econometrics, each of whom gives an account of the current state of the art in their own field and indicate the direction that they think it will take in the next ten years. The fields covered are grouped into three categories: the microfoundations of macroeconomics, where Malinvaud evaluates the theory of resource allocation and Hildenbrand examines the empirical content of economic thories; markets and and organizations, where both Gabszewicz and D'Aspremont et al. look at imperfect competition and general equilibrium, Scotchmer and Thiess consider spatial economics, Ponssard the future of managerial economics, while Van Damme looks at the next stage of game theory; and econometrics, where Gourieroux reviews econometric modelling in general, Maravall looks at time series, Lubrand and Bauwens examine Bayesian analysis, and Blundell looks at the rapidly expanding area of microeconometrics.

Nonlinear Dynamics and Economics, first published in 1997, presents developments in nonlinear economic dynamics along with related research from associated fields, including mathematics, statistics, biology, and physics. Specific areas covered include instability in economic theory, nonlinearity in financial markets, tests for nonlinearity and chaos, frequency domain methods, nonlinear business cycles, and nonlinear prediction and forecasting. This volume comprises the tenth in the International Symposia in Economic Theory and Econometrics series under the general editorship of William Barnett. This proceedings volume includes revisions of the most important papers presented at a conference held at the European University Institute in Florence on July 6-17, 1992, along with revisions of the related, invited papers presented at the annual meetings of the American Statistical Association held in San Francisco on August 8-12, 1993.

A comprehensive survey on current and future developments in long memory analysis. The book assembles three different strands of long memory analysis: statistical literature – including tests – on the properties of LRD processes; mathematical literature on stochastic processes; and models from economic theory providing. The text is aimed at economists, econometricians, and statisticians interested in the study of long memory in economics.

A comprehensive survey on current and future developments in long memory analysis. The book assembles three different strands of long memory analysis: statistical literature - including tests - on the properties of LRD processes; mathematical literature on stochastic processes; and models from economic theory providing. The text is aimed at economists, econometricians, and statisticians interested in the study of long memory in economics.

This volume contains a selection of contributions presented at the WEHIA02 (Workshop on Economies with Heterogeneous Interacting Agents), which was held at the Abdus Salam International Centre for Physics of Trieste, Italy, on May 29- 31, under the auspices of Exystence, Complex System network of excellence . WEHIA02 is the 7th edition of a workshop, which was held for the first time at the University of Ancona, Italy , on 1996 (1), as a one-week series of seminars for the Italian PhD program . Ancona hosted the event in the years 1997 and 1998 (2) , before it moved to Genoa 1999 (3), Marseille 2000 (4) , Maastricht 2001 (5), and finally to Trieste 2002. The 2003 workshop was held in Kid , Germany, while the next editions will be in Kyoto, Japan (2004) and Essex, UK (2005). The full list of participants, titles of the invited lectures, papers and posters of WEHIA can be found in http ://econ . dea. it/wehia2. The workshop has been always very informal aiming to put together sch- ars of different disciplines working on interaction of heterogeneous "so- thing " (economists, physicists, biologists) . To facilitate participation there has not been conference fee . It aimed to be a locus for communicate and exchange results and experiences . Several collaborations started with the Workshop and it is not without pride that the organizers claim such a result. The WEHIA has had two pars: a pars desiruens and a pars adestruens.

3 Domenico Delli Gatti!, Mauro GallegatF, Alan P. Kirman ! ITEMQ, Catholic University, Milan, Italy 2 MET, University of Teramo, Italy 3 GREQAM, Universite d'Aix-Marseille, Ecole des Hautes Etudes en Sciences Sociales, and Institut Universitaire de France The economics of heterogeneity This volume contains a set of papers which pursue the aim of examining how the properties of aggregate economic variables are influenced by the actions and interactions of individuals. This has been the central theme of a series of workshops held at the University of Ancona, Italy, since 1996, whose general title is Workshops on Economics with Heterogeneous Interactive Agents (WEHIA for short). ! Considering the economy as a complex evolving system of interacting agents, one has to take seriously three fundamental issues: * the heterogeneity of the agents in the economy, * the ways in which agents interact, * the dynamic process which governs the evolution of the individual and the aggregate variables. The third issue concerns especially the idea that agents learn and adapt rather than calculate optimally (Anderson et aI. , 1988; Arthur et aI. , 1997; Allen, 1988.) As to the first issue, general equilibrium theory allows, of course, agents to be as heterogeneous as one wants but as the Sonnenschein-Mantel-Debreu results have I The papers published in this book are a selected sample of the papers presented at the 3rd WEHIA workshop held at the University of Ancona on May 29-30,1998.

A comprehensive survey on current and future developments in long memory analysis. The book assembles three different strands of long memory analysis: statistical literature – including tests – on the properties of LRD processes; mathematical literature on stochastic processes; and models from economic theory providing. The text is aimed at economists, econometricians, and statisticians interested in the study of long memory in economics.

This volume contains a selection of contributions presented at the WEHIA02 (Workshop on Economies with Heterogeneous Interacting Agents), which was held at the Abdus Salam International Centre for Physics of Trieste, Italy, on May 29- 31, under the auspices of Exystence, Complex System network of excellence . WEHIA02 is the 7th edition of a workshop, which was held for the first time at the University of Ancona, Italy , on 1996 (1), as a one-week series of seminars for the Italian PhD program . Ancona hosted the event in the years 1997 and 1998 (2) , before it moved to Genoa 1999 (3), Marseille 2000 (4) , Maastricht 2001 (5), and finally to Trieste 2002. The 2003 workshop was held in Kid , Germany, while the next editions will be in Kyoto, Japan (2004) and Essex, UK (2005). The full list of participants, titles of the invited lectures, papers and posters of WEHIA can be found in http ://econ . dea. it/wehia2. The workshop has been always very informal aiming to put together sch- ars of different disciplines working on interaction of heterogeneous "so- thing " (economists, physicists, biologists) . To facilitate participation there has not been conference fee . It aimed to be a locus for communicate and exchange results and experiences . Several collaborations started with the Workshop and it is not without pride that the organizers claim such a result. The WEHIA has had two pars: a pars desiruens and a pars adestruens.

This volume contains papers that provide an analysis of topics in the following areas: Agent Based Models, Non-linear Time Series Analysis, Financial Market Dynamics, Econo-physics, Deterministic Chaos, Macroeconomic Dynamics.Economics: Complex Windows, does not present contributions to the sterile debate as to the merits of the different grand, or potentially grand paradigms of economics. Rather it offers a balanced collection of methodological advances which can be applied to concrete economic problems. Starting with a presentation of the "complexity approach" to economics, it goes on to provide a collection of applications to areas such as the analysis of market imperfections, risk assessment, non-linear dynamics, forecasting and highly irregular fluctuations. The basic idea is to encourage economic researchers to embrace a more open and pragmatic approach to economics rather than to reluctantly move in this direction as if it were somehow a betrayal of established dogma.

“In some ways, the e?ect of achieving understanding is to reverse completely our initial attitude of mind. For everyone starts (as we have said) by being perplexed by some fact or other: for instance... the fact that the diagonal of a square is incommensurable with the side. Anyone who has not yet seen why the side and the diagonal have no common unit regards this as quite extra- dinary. But one ends up in the opposite frame of mind... for nothing would so much ?abbergast a mathematician as if the diagonal and side of a square were to become commensurable”. [Aristotele] This is the ?rst volume of a new series entitled “New Economic Windows”. Each volume in the series will, we hope, provide pointers towards a better understanding of the nature of economic phenomena and help to “reverse our initial state of mind” as economists. As H. Simon observed, Economics must be considered a “hard”, (in the sense of di?cult rather than precise), science. As he cogently argued, the problems dealt with are so complex they “cannot simply be reduced to analytically solvable models or decomposed into sepa- 1 rate sub processes”. In this he was following on from Einstein who, many years earlier, when asked why he had not turned his attention to economics said that he found it too di?cult a subject to handle scienti?cally.

Economics: Beyond the Millennium contains articles by leading authorities in various fields of economic theory and econometrics, each of whom gives an account of the current state of the art in their own field and indicate the direction that they think it will take in the next ten years. The fields covered are grouped into three categories: the microfoundations of macroeconomics, where Malinvaud evaluates the theory of resource allocation and Hildenbrand examines the empirical content of economic thories; markets and and organizations, where both Gabszewicz and D'Aspremont et al. look at imperfect competition and general equilibrium, Scotchmer and Thiess consider spatial economics, Ponssard the future of managerial economics, while Van Damme looks at the next stage of game theory; and econometrics, where Gourieroux reviews econometric modelling in general, Maravall looks at time series, Lubrand and Bauwens examine Bayesian analysis, and Blundell looks at the rapidly expanding area of microeconometrics.

Nonlinear Dynamics and Economics, first published in 1997, presents developments in nonlinear economic dynamics along with related research from associated fields, including mathematics, statistics, biology, and physics. Specific areas covered include instability in economic theory, nonlinearity in financial markets, tests for nonlinearity and chaos, frequency domain methods, nonlinear business cycles, and nonlinear prediction and forecasting. This volume comprises the tenth in the International Symposia in Economic Theory and Econometrics series under the general editorship of William Barnett. This proceedings volume includes revisions of the most important papers presented at a conference held at the European University Institute in Florence on July 6-17, 1992, along with revisions of the related, invited papers presented at the annual meetings of the American Statistical Association held in San Francisco on August 8-12, 1993.

A comprehensive survey on current and future developments in long memory analysis. The book assembles three different strands of long memory analysis: statistical literature – including tests – on the properties of LRD processes; mathematical literature on stochastic processes; and models from economic theory providing. The text is aimed at economists, econometricians, and statisticians interested in the study of long memory in economics.

A comprehensive survey on current and future developments in long memory analysis. The book assembles three different strands of long memory analysis: statistical literature - including tests - on the properties of LRD processes; mathematical literature on stochastic processes; and models from economic theory providing. The text is aimed at economists, econometricians, and statisticians interested in the study of long memory in economics.

This volume contains a selection of contributions presented at the WEHIA02 (Workshop on Economies with Heterogeneous Interacting Agents), which was held at the Abdus Salam International Centre for Physics of Trieste, Italy, on May 29- 31, under the auspices of Exystence, Complex System network of excellence . WEHIA02 is the 7th edition of a workshop, which was held for the first time at the University of Ancona, Italy , on 1996 (1), as a one-week series of seminars for the Italian PhD program . Ancona hosted the event in the years 1997 and 1998 (2) , before it moved to Genoa 1999 (3), Marseille 2000 (4) , Maastricht 2001 (5), and finally to Trieste 2002. The 2003 workshop was held in Kid , Germany, while the next editions will be in Kyoto, Japan (2004) and Essex, UK (2005). The full list of participants, titles of the invited lectures, papers and posters of WEHIA can be found in http ://econ . dea. it/wehia2. The workshop has been always very informal aiming to put together sch- ars of different disciplines working on interaction of heterogeneous "so- thing " (economists, physicists, biologists) . To facilitate participation there has not been conference fee . It aimed to be a locus for communicate and exchange results and experiences . Several collaborations started with the Workshop and it is not without pride that the organizers claim such a result. The WEHIA has had two pars: a pars desiruens and a pars adestruens.

3 Domenico Delli Gatti!, Mauro GallegatF, Alan P. Kirman ! ITEMQ, Catholic University, Milan, Italy 2 MET, University of Teramo, Italy 3 GREQAM, Universite d'Aix-Marseille, Ecole des Hautes Etudes en Sciences Sociales, and Institut Universitaire de France The economics of heterogeneity This volume contains a set of papers which pursue the aim of examining how the properties of aggregate economic variables are influenced by the actions and interactions of individuals. This has been the central theme of a series of workshops held at the University of Ancona, Italy, since 1996, whose general title is Workshops on Economics with Heterogeneous Interactive Agents (WEHIA for short). ! Considering the economy as a complex evolving system of interacting agents, one has to take seriously three fundamental issues: * the heterogeneity of the agents in the economy, * the ways in which agents interact, * the dynamic process which governs the evolution of the individual and the aggregate variables. The third issue concerns especially the idea that agents learn and adapt rather than calculate optimally (Anderson et aI. , 1988; Arthur et aI. , 1997; Allen, 1988.) As to the first issue, general equilibrium theory allows, of course, agents to be as heterogeneous as one wants but as the Sonnenschein-Mantel-Debreu results have I The papers published in this book are a selected sample of the papers presented at the 3rd WEHIA workshop held at the University of Ancona on May 29-30,1998.

A comprehensive survey on current and future developments in long memory analysis. The book assembles three different strands of long memory analysis: statistical literature – including tests – on the properties of LRD processes; mathematical literature on stochastic processes; and models from economic theory providing. The text is aimed at economists, econometricians, and statisticians interested in the study of long memory in economics.

This volume contains a selection of contributions presented at the WEHIA02 (Workshop on Economies with Heterogeneous Interacting Agents), which was held at the Abdus Salam International Centre for Physics of Trieste, Italy, on May 29- 31, under the auspices of Exystence, Complex System network of excellence . WEHIA02 is the 7th edition of a workshop, which was held for the first time at the University of Ancona, Italy , on 1996 (1), as a one-week series of seminars for the Italian PhD program . Ancona hosted the event in the years 1997 and 1998 (2) , before it moved to Genoa 1999 (3), Marseille 2000 (4) , Maastricht 2001 (5), and finally to Trieste 2002. The 2003 workshop was held in Kid , Germany, while the next editions will be in Kyoto, Japan (2004) and Essex, UK (2005). The full list of participants, titles of the invited lectures, papers and posters of WEHIA can be found in http ://econ . dea. it/wehia2. The workshop has been always very informal aiming to put together sch- ars of different disciplines working on interaction of heterogeneous "so- thing " (economists, physicists, biologists) . To facilitate participation there has not been conference fee . It aimed to be a locus for communicate and exchange results and experiences . Several collaborations started with the Workshop and it is not without pride that the organizers claim such a result. The WEHIA has had two pars: a pars desiruens and a pars adestruens.

This volume contains papers that provide an analysis of topics in the following areas: Agent Based Models, Non-linear Time Series Analysis, Financial Market Dynamics, Econo-physics, Deterministic Chaos, Macroeconomic Dynamics.Economics: Complex Windows, does not present contributions to the sterile debate as to the merits of the different grand, or potentially grand paradigms of economics. Rather it offers a balanced collection of methodological advances which can be applied to concrete economic problems. Starting with a presentation of the "complexity approach" to economics, it goes on to provide a collection of applications to areas such as the analysis of market imperfections, risk assessment, non-linear dynamics, forecasting and highly irregular fluctuations. The basic idea is to encourage economic researchers to embrace a more open and pragmatic approach to economics rather than to reluctantly move in this direction as if it were somehow a betrayal of established dogma.

“In some ways, the e?ect of achieving understanding is to reverse completely our initial attitude of mind. For everyone starts (as we have said) by being perplexed by some fact or other: for instance... the fact that the diagonal of a square is incommensurable with the side. Anyone who has not yet seen why the side and the diagonal have no common unit regards this as quite extra- dinary. But one ends up in the opposite frame of mind... for nothing would so much ?abbergast a mathematician as if the diagonal and side of a square were to become commensurable”. [Aristotele] This is the ?rst volume of a new series entitled “New Economic Windows”. Each volume in the series will, we hope, provide pointers towards a better understanding of the nature of economic phenomena and help to “reverse our initial state of mind” as economists. As H. Simon observed, Economics must be considered a “hard”, (in the sense of di?cult rather than precise), science. As he cogently argued, the problems dealt with are so complex they “cannot simply be reduced to analytically solvable models or decomposed into sepa- 1 rate sub processes”. In this he was following on from Einstein who, many years earlier, when asked why he had not turned his attention to economics said that he found it too di?cult a subject to handle scienti?cally.