Economies with heterogeneous interacting learning agents
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DOI: 10.1007/s11403-013-0121-1
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- Alan Kirman, 2011.
"Learning in Agent-based Models,"
Eastern Economic Journal, Palgrave Macmillan;Eastern Economic Association, vol. 37(1), pages 20-27.
- Alan Kirman, 2010. "Learning in agent based models," Working Papers halshs-00545169, HAL.
- Foley Duncan K., 1994. "A Statistical Equilibrium Theory of Markets," Journal of Economic Theory, Elsevier, vol. 62(2), pages 321-345, April.
- Delli Gatti, Domenico & Gallegati, Mauro & Greenwald, Bruce & Russo, Alberto & Stiglitz, Joseph E., 2010. "The financial accelerator in an evolving credit network," Journal of Economic Dynamics and Control, Elsevier, vol. 34(9), pages 1627-1650, September.
- Alan Kirman, 2012. "Can Artificial Economies Help us Understand Real Economies?," Revue de l'OFCE, Presses de Sciences-Po, vol. 0(5), pages 15-41.
- Tesfatsion, Leigh & Judd, Kenneth L., 2006. "Handbook of Computational Economics, Vol. 2: Agent-Based Computational Economics," Staff General Research Papers Archive 10368, Iowa State University, Department of Economics.
- Stiglitz, Joseph E, 1976. "The Efficiency Wage Hypothesis, Surplus Labour, and the Distribution of Income in L.D.C.s," Oxford Economic Papers, Oxford University Press, vol. 28(2), pages 185-207, July.
- Sargent, Thomas J., 1993. "Bounded Rationality in Macroeconomics: The Arne Ryde Memorial Lectures," OUP Catalogue, Oxford University Press, number 9780198288695.
- Simone Alfarano & Thomas Lux & Friedrich Wagner, 2005. "Estimation of Agent-Based Models: The Case of an Asymmetric Herding Model," Computational Economics, Springer;Society for Computational Economics, vol. 26(1), pages 19-49, August.
- Bruce C. Greenwald & Joseph E. Stiglitz, 1993.
"Financial Market Imperfections and Business Cycles,"
The Quarterly Journal of Economics, President and Fellows of Harvard College, vol. 108(1), pages 77-114.
- Bruce C. Greenwald & Joseph E. Stiglitz, 1988. "Financial Market Imperfections and Business Cycles," NBER Working Papers 2494, National Bureau of Economic Research, Inc.
- Stiglitz, Joseph E, 1975.
"The Theory of "Screening," Education, and the Distribution of Income,"
American Economic Review, American Economic Association, vol. 65(3), pages 283-300, June.
- Joseph E. Stiglitz, 1973. "The Theory of 'Screening', Education, and the Distribution of Income," Cowles Foundation Discussion Papers 354, Cowles Foundation for Research in Economics, Yale University.
- Leigh Tesfatsion & Kenneth L. Judd (ed.), 2006. "Handbook of Computational Economics," Handbook of Computational Economics, Elsevier, edition 1, volume 2, number 2.
- Domenico Delli Gatti & Corrado Di Guilmi & Mauro Gallegati & Simone Landini, 2012. "Reconstructing Aggregate Dynamics in Heterogeneous Agents Models. A Markovian Approach," Revue de l'OFCE, Presses de Sciences-Po, vol. 0(5), pages 117-146.
- Weidlich, Wolfgang & Braun, Martin, 1992. "The Master Equation Approach to Nonlinear Economics," Journal of Evolutionary Economics, Springer, vol. 2(3), pages 233-265, October.
- Stiglitz, Joseph E., 1973. "Taxation, corporate financial policy, and the cost of capital," Journal of Public Economics, Elsevier, vol. 2(1), pages 1-34, February.
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Cited by:
- M. L. Bertotti & G. Modanese, 2016. "Mathematical models describing the effects of different tax evasion behaviors," Papers 1701.02662, arXiv.org.
- Antonelli, Cristiano, 2017. "From the Economics of Information to the Economics of Knowledge. Length: pages 39," Department of Economics and Statistics Cognetti de Martiis. Working Papers 201714, University of Turin.
- Özge Dilaver & Robert Calvert Jump & Paul Levine, 2018.
"Agent‐Based Macroeconomics And Dynamic Stochastic General Equilibrium Models: Where Do We Go From Here?,"
Journal of Economic Surveys, Wiley Blackwell, vol. 32(4), pages 1134-1159, September.
- Özge Dilaver & Robert Jump & Paul Levine, 2016. "Agent-based Macroeconomics and Dynamic Stochastic General Equilibrium Models: Where do we go from here?," School of Economics Discussion Papers 0116, School of Economics, University of Surrey.
- Antonelli, Cristiano, 2017. "From the Economics of Information to the Economics of Knowledge," Department of Economics and Statistics Cognetti de Martiis LEI & BRICK - Laboratory of Economics of Innovation "Franco Momigliano", Bureau of Research in Innovation, Complexity and Knowledge, Collegio 201706, University of Turin.
- Sven Banisch & Eckehard Olbrich, 2017. "The Coconut Model with Heterogeneous Strategies and Learning," Journal of Artificial Societies and Social Simulation, Journal of Artificial Societies and Social Simulation, vol. 20(1), pages 1-14.
- M. L. Bertotti & G. Modanese, 2018. "Mathematical models describing the effects of different tax evasion behaviors," Journal of Economic Interaction and Coordination, Springer;Society for Economic Science with Heterogeneous Interacting Agents, vol. 13(2), pages 351-363, July.
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More about this item
Keywords
Heterogeneous interacting ABM; Learning; Master equations; C5; C6; D83; E1; E3;All these keywords.
JEL classification:
- C5 - Mathematical and Quantitative Methods - - Econometric Modeling
- C6 - Mathematical and Quantitative Methods - - Mathematical Methods; Programming Models; Mathematical and Simulation Modeling
- D83 - Microeconomics - - Information, Knowledge, and Uncertainty - - - Search; Learning; Information and Knowledge; Communication; Belief; Unawareness
- E1 - Macroeconomics and Monetary Economics - - General Aggregative Models
- E3 - Macroeconomics and Monetary Economics - - Prices, Business Fluctuations, and Cycles
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