Segismundo Samuel Izquierdo Millán

Professor. Catedrático, Universidad de Valladolid. Department of  Industrial Organization Escuela de Ingenierías Industriales Paseo Prado de la Magdalena 3-5 47011 Valladolid E-mail: segismundo.izquierdo(at)uva.es

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FIELDS OF SPECIALIZATION AND INTEREST

• Game theory, Evolutionary game theory, Agent-based modelling, Artificial intelligence.
• Microeconomics, Econometrics, Markov chains, Stochastic processes.

POSITIONS AND WORK EXPERIENCE

• Lecturer in Economics, University of Valladolid (since 2001)
• Visiting Professor, Department of Mathematics, University of British Columbia, Canada (2023-2024)
• Fulbright Scholar, Department of Economics, University of Wisconsin-Madison, USA (2021)
• Visiting Researcher, Department of Economics, University of Wisconsin-Madison, USA (2018)
• Visiting Researcher, Department of Economics, University of Wisconsin-Madison, USA (2016)
• Visiting Researcher, European University Institute, Italy (2009-2010)
• Visiting Researcher, Stockholm School of Economics, Sweden (2006)
• Visiting Researcher, The Macaulay Land Use Research Institute, Scotland (2005)
• Visiting Researcher, The Macaulay Land Use Research Institute, Scotland (2004)
• Business Consultant, PricewaterhouseCoopers Consulting, London, Prague, Madrid (1998-2002)

2024 BOOK: AGENT-BASED EVOLUTIONARY GAME DYNAMICS

This book is a guide to implement and analyze Agent-Based Models within the framework of Evolutionary Game Theory, using NetLogo.

Agent-Based Evolutionary Game Dynamics. Izquierdo, L.R., Izquierdo, S.S. and Sandholm, W.H. 2024. University of Wisconsin Pressbooks.
You can find the printed edition at Amazon. [READ ONLINE]

Working papers

• Conventions in Repeated Games with Endogenous Separation.
  Izquierdo, S.S. & Izquierdo, L.R..
  Working paper
  
• Statistical inference in games: stability of pure equilibria.
  Izquierdo, S.S. & Izquierdo, L.R..
  Working paper
  
• Artificial Economics: A critical review [Download] [See presentation]
  Izquierdo, L.R. & Izquierdo, S.S., Galán J.M. & Santos, J.I.

SOFTWARE TOOLS

• Pair approximation for 2x2 symmetric games on regular networks.
  Izquierdo, L.R., Izquierdo, S.S. & Hauert, C. (2024). Software. DOI: 10.5281/zenodo.10975163.
  
  
• Link to MATHEMATICA DEMONSTRATIONS
• ABED: Agent-Based Simulation of Evolutionary Game Dynamics | [abed-1pop] | [abed-2pop] | [Presentation] [Related paper, publishers's site] | [Related working Paper] | [Online appendix]
• EvoDyn-3s: A Mathematica Computable Document to Analyze Evolutionary Dynamics in 3-Strategy Games [Paper] | [Software]
  

SELECTED PAPERS

• Positive and negative selective assortment.
  Izquierdo, S.S., Izquierdo, L.R. & Hauert, C. (2025) Journal of Theoretical Biology vol. 608, 112129. DOI: 10.1016/j.jtbi.2025.112129
  [Paper] | [Software]
  
  
• Social simulation models as refuting machines
  Mauhe, N., Izquierdo, L.R. & Izquierdo, S.S. (2023) Journal of Artificial Societies and Social Simulation 26(2)8. DOI: 10.18564/jasss.5076
  [Download] | [Download postprint in PDF] | [Software]
  
• Strategy sets closed under payoff sampling
  Izquierdo, S.S. & Izquierdo, L.R. (2023) Games and Economic Behavior, 138, pp. 126-142 [Working paper] | [Download at publishers's site] | [Software 1 (EvoDyn-3s)] | [Software 2 (BEP-3s-sp)]
  
• Stability of Strict Equilibria in Best Experienced Payoff Dynamics: Simple Formulas and Applications
  Izquierdo, S.S. & Izquierdo, L.R. (2022) Journal of Economic Theory, 105553 [Download] | [Software 1 (EvoDyn-3s)] | [Software 2 (BEP-TCG)]
  
• Fast and Scalable Global Convergence in Single-Optimum Decentralized Coordination Problems
  Izquierdo, L.R., Izquierdo, S.S. & Rodríguez, J. (2022) in IEEE Transactions on Control of Network Systems, vol. 9, issue 4, pp. 1937-1948. doi: 10.1109/TCNS.2022.3181545.
  [Download at publishers's site] | [Accepted version] | [Presentation] | [Agent-based model nBEPA1 in SOC games] | [Agent-based model nBEPA1 in SOC games played in networks]
  
• “Test two, choose the better" leads to high cooperation in the Centipede game
  Izquierdo, S.S. & Izquierdo, L.R. (2021) Journal of Dynamics and Games, vol. 9, issue 4, pp. 461-498.
  [Download at publishers's site] | [Working Paper] | [Agent-based model] | [Mathematica notebook]
  
• Repeated Games with Endogenous Separation
  Izquierdo, S.S., Izquierdo, L.R. and van Veelen, M. (2021) Universidad de Valladolid. Mimeo.
  Manuscript
  
• "Stability for Best Experienced Payoff Dynamics".
  Sandholm, W.H., Izquierdo, S.S. & Izquierdo, L.R. (2020) Journal of Economic Theory, 185, 104957.
  [Download at publishers's site] | [Working Paper] | [Mathematica program]
  
  
• Best Experienced Payoff Dynamics and Cooperation in the Centipede Game
  Sandholm, W.H., Izquierdo, S.S. & Izquierdo, L.R. (2019) Theoretical Economics 14, 1347–1385
  [Download] | [Online appendix] | [Mathematica notebook]
  
• An Introduction to ABED: Agent-Based Simulation of Evolutionary Game Dynamics
  Izquierdo, L.R., Izquierdo, S.S. & Sandholm, W.H. (2019). Games and Economic Behavior 118, 434-462.
  [Download at publishers's site] | [Working Paper] | [Online appendix] | [abed-1pop] | [abed-2pop] | [Presentation]
  
  
• EvoDyn-3s: A Mathematica Computable Document to Analyze Evolutionary Dynamics in 3-Strategy Games
  Izquierdo, L.R., Izquierdo, S.S. & Sandholm, W.H. (2018). SoftwareX, 7, pp. 226-233.
  [Download] | [Software]
  
  
  
• Mamdani Fuzzy Systems for Modelling and Simulation: A Critical Assessment
  Izquierdo S.S. & Izquierdo, L.R. (2018). Journal of Artificial Societies and Social Simulation 21(3)2. DOI: 10.18564/jasss.3660
  [Download]
• Mixing and diffusion in a two-type population
  Izquierdo, S.S., Izquierdo, L.R. & López-Pintado, D. (2018). Royal Society Open Science, 5(2) 172102.
  [Download] | [Presentation] | [NetLogo model] | [Mathematica demonstration]
  
  
• Economía Artificial: una valoración crítica [Download]
  Izquierdo, S.S., Izquierdo, L.R. , Galán J.M. & Santos, J.I. (2016). Revista de Métodos Cuantitativos para la Economía y la Empresa, vol. 22, pp. 36-54. [es]
• The "Win-Continue, Lose-Reverse" Rule in Oligopolies: Robustness of Collusive Outcomes
  Izquierdo, S.S. & Izquierdo, L.R. (2015). Advances in Complex Systems 18(5) 6
  [Download at Publisher's website ] | [Cournot Model]] | [Bertrand Model]]
• Fuzzy Logic for Social Simulation using NetLogo
  Izquierdo, L.R. , Olaru, D., Izquierdo S.S., Purchase, S. & Soutar, G.N. (2015). Journal of Artificial Societies and Social Simulation 18(4)1. DOI: 10.18564/jasss.2885
  [Download] | [Extension, source code, user guide, cheat sheet, and a sample model with a tutorial] | [Blog post]
• The "Win-Continue, Lose-Reverse" Rule in Cournot Oligopolies: Robustness of Collusive Outcomes [Unformatted version]
  Izquierdo, S.S. & Izquierdo, L.R. (2015). In Advances in Artificial Economics, Amblard, F., Miguel, F.J., Blanchet, A., Gaudou, B. (Eds.) Lecture Notes in Economics and Mathematical Systems, Vol. 676, pp 33-44.
  [Download at Publisher's website] |[Model]
• Leave and let leave: A sufficient condition to explain the evolutionary emergence of cooperation [Download]
  Izquierdo, L.R. , Izquierdo, S.S. & Vega-Redondo, F. (2014). Journal of Economic Dynamics & Control.
  [Unformatted version] | [Computational model] | [Presentation]

• Stochastic Approximation to Understand Simple Simulation Models. [Download] | [Download at publisher]
  Izquierdo, S.S. & Izquierdo, L.R. (2013). Journal of Statistical Physics, 151 (1) pp. 254-276.
  [See model]
  
  

• Combining Mathematical and Simulation Approaches to Understand the Dynamics of Computer Models. [Download unformatted version] | [Download at publisher]
  Izquierdo, L.R., Izquierdo, S.S., Galán, J.M. & Santos, J.I. (2013). In Simulating Social Complexity: A Handbook. Series: Understanding Complex Systems. Springer-Verlag, pp. 235-271.

• Checking Simulations: Detecting and Avoiding Errors and Artefacts. [Download]
  Galán, J.M., Izquierdo, L.R., Izquierdo, S.S., Santos, J.I., del Olmo, R. & López-Paredes (2013). In Simulating Social Complexity: A Handbook. Series: Understanding Complex Systems. Springer-Verlag, pp. 95-116.

• 7-page introduction to classical, learning, and evolutionary game theory. [Download] | [Download at publisher]
  Izquierdo, L.R. , Izquierdo, S.S. & Vega-Redondo, F. (2012).
  In N. M. Seel (Ed.) Encyclopedia of the Sciences of Learning, Part 12, pp. 1782-1788. ISBN: 978-1-4419-1427-9. New York: Springer.

• 4-page introduction to reinforcement learning. [Download] | [Download at publisher]
  Izquierdo, L.R. & Izquierdo, S.S. (2012).
  In N. M. Seel (Ed.) Encyclopedia of the Sciences of Learning, Part 18, pp. 2796-2799. ISBN: 978-1-4419-1427-9. New York: Springer.

• Strictly Dominated Strategies in the Replicator-Mutator Dynamics.
  Izquierdo, S.S., Izquierdo, L.R. (2011).
  Games 2011, 2(3), 355-364; doi:10.3390/g2030355
  [Model (The replicator-mutator dynamics with 3 strategies)]
  [ http://demonstrations.wolfram.com/ReplicatorMutatorDynamicsWithThreeStrategies/ ]
  
  
• The Option to Leave: Conditional Dissociation in the Evolution of Cooperation [Download]
  Izquierdo, S.S., Izquierdo, L.R. & Vega-Redondo, F. (2010).
  Journal of Theoretical Biology 267: 76-84. doi:10.1016/j.jtbi.2010.07.039
  [Unformatted version] | [Supplementary material] | [Presentation] | [Model (with constant population)]
  | [Model (with fluctuating population)]
  
• Techniques to understand computer simulations.
  Izquierdo, L.R., Izquierdo, S.S., Galán J.M. & Santos, J.I. (2009).
  Journal of Artificial Societies and Social Simulation 12(1)6
  [Document + models (.zip)]
  
  
• Errors and artefacts in agent-based modelling.
  Galán J.M., Izquierdo, L.R., Izquierdo, S.S., Santos, J.I., Olmo, R., López-Paredes, A. & Edmonds, B. (2009).
  Journal of Artificial Societies and Social Simulation 12(1)1
  
• Reinforcement Learning Dynamics in Social Dilemmas.
  Izquierdo, S.S., Izquierdo, L.R. and Gotts, N.M. (2008)
  Journal of Artificial Societies and Social Simulation , 11(2)1
  
  
• Dynamics of the Bush-Mosteller Learning Algorithm in 2x2 Games.
  Izquierdo, L.R., Izquierdo, S.S.(2008)
  Chapter 11 in Reinforcement Learning. Theory and Applications, edited by Cornelius Weber, Mark Elshaw and Norbert Michael Mayer.
  I-Tech Education and Publishing, Vienna, Austria. ISBN 978-3-902613-14-1.
  
• Transient and asymptotic dynamics of reinforcement learning in games
  Games and Economic Behavior, Volume 61, Issue 2, pp. 259–276.
  Izquierdo, L.R., Izquierdo, S.S., Gotts, N.M. and Polhill, J.G. (2007)
  http://dx.doi.org/10.1016/j.geb.2007.01.005
  See Presentation
• The impact of quality uncertainty without asymmetric information on market efficiency.
  Izquierdo, S.S. and Izquierdo, L.R. (2007)
  Journal of Business Research, Volume 60, Issue 8, pp. 858-867.
  http://dx.doi.org/10.1016/j.jbusres.2007.02.010 . See Netlogo model.
  
  
• Publishing science in the digital age. The case of Neurocirugía
  Izquierdo, S.S., Izquierdo, L.R. and Izquierdo, J.M. (2007)
  Neurocirugia, Volume 18, Issue 3, pp. 193-200.
  http://revistaneurocirugia.com/web/artics/v18n3/1.pdf
• On the Structural Robustness of Evolutionary Models of Cooperation.
  Izquierdo, S.S. and Izquierdo, L.R. (2006)
  Lecture Notes in Computer Science 4224, 172-182.
  http://dx.doi.org/10.1007/11875581_21
• Market Failure Caused by Quality Uncertainty.
  Izquierdo, S.S., Izquierdo, L.R., Galán J.M. and Hernández, C. (2005)
  - In Mathieu P., Beaufils, B., and Brandouy, O. (Eds), Artificial Economics -
  Lecture Notes in Economics and Mathematical Systems, 564, 203-213.
  http://dx.doi.org/10.1007/3-540-28547-4_17

Other papers

• Izquierdo, S.S. (2011). Breve introducción a HubNet.
  
• Izquierdo, S.S. (2010). Book review: "Nonlinear Dynamics in Economics, Finance and the Social Sciences. Essays in Honour of John Barkley Rosser Jr" by Bischi, Gian Italo, Chiarella, Carl and Gardini, Laura (eds.) Journal of Artificial Societies and Social Simulation 13(3)
  
• Pascual, J.A., Galán, J.M., Izquierdo, L.R., Santos, J.I., Izquierdo, S.S., González, J. (2009).
  Una herramienta didáctica para la enseñanza de la teoría de juegos mediante internet.
  EDUTEC, Revista Electrónica de Tecnología Educativa, 29.
• Galán Ordax, J.M., Izquierdo Millán, L.R., Izquierdo Millán, S.S., López Paredes, A., Pascual Ruano, J.A., Posada Calvo, M., Santos Martín, J.I. & Villafáñez Cardeñoso, F.A. (2007).
  LABEXNET: un Laboratorio de Economía Experimental en Internet.
  RELIEVE Revista ELectrónica de Investigación y EValuación Educativa, 13(1), 105-125.
• Izquierdo, S.S, Hernández, C. and Pajares, J. (2005).
  State Space Modelling of Cointegrated Systems using Subspace Algorithms.
  In Best-of-Book AMSE 2004, MS’2004 Spain, 35-46.

Teaching materials (Spanish) - Material docente

• Ficheros para prácticas en Excel de microeconomía y empresa. Uso libre manteniendo la referencia al autor.
• Ficheros para prácticas de laboratorio en grupo de Teoría de Juegos, modelo de Cournot. Corre sobre Netlogo 4.1.3. Versión inicial realizada como Proyecto Fin de Carrera por Jacinto Merino Luis. Uso libre manteniendo la referencia a los autores.
• Fichero para prácticas en Excel de introducción al análisis de estados contables.

DOCTORAL STUDIES

• Ph.D. (System Identification, Econometrics), University of Valladolid, Spain. Special Award 2004-5.
• Dissertation: Análisis de Sistemas Cointegrados mediante Métodos de subespacios (Analysis of Cointegrated Systems using Subspace Algorithms).

PREDOCTORAL STUDIES

• MSc Industrial Engineering. 1998. Thesis: “A Comparison of Genetic Algorithms and Backpropagation for the Training of Neural Networks”.