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Learning and dropout in contests: an experimental approach

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  • Francesco Fallucchi

    (Luxembourg Institute of Socio-Economic Research (LISER))

  • Jan Niederreiter

    (IMT Institute for Advanced studies)

  • Massimo Riccaboni

    (IMT Institute for Advanced studies)

Abstract

We design an experiment to study investment behavior in different repeated contest settings, varying the uncertainty of the outcomes and the number of participants in contests. We find decreasing over-expenditures and a higher rate of ‘dropout’ in contests with high uncertainty over outcomes (winner-take-all contests), while we detect a quick convergence toward equilibrium predictions and a near to full participation when this type of uncertainty vanishes (proportional-prize contests). These results are robust to changes in the number of contestants. A learning parameter estimation using the experience-weighted attraction (EWA) model suggests that subjects adopt different learning modes across different contest structures and helps to explain expenditure patterns deviating from theoretical predictions.

Suggested Citation

  • Francesco Fallucchi & Jan Niederreiter & Massimo Riccaboni, 2021. "Learning and dropout in contests: an experimental approach," Theory and Decision, Springer, vol. 90(2), pages 245-278, March.
    • Handle: RePEc:kap:theord:v:90:y:2021:i:2:d:10.1007_s11238-020-09783-z
    DOI: 10.1007/s11238-020-09783-z
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    as
    1. Philip Brookins & Dmitry Ryvkin, 2014. "An experimental study of bidding in contests of incomplete information," Experimental Economics, Springer;Economic Science Association, vol. 17(2), pages 245-261, June.
    2. Fallucchi, Francesco & Renner, Elke & Sefton, Martin, 2013. "Information feedback and contest structure in rent-seeking games," European Economic Review, Elsevier, vol. 64(C), pages 223-240.
    3. Fabio Pammolli & Massimo Riccaboni & Laura Magazzini, 2010. "The productivity crisis in pharmaceutical R&D," Working Papers 06/2010, University of Verona, Department of Economics.
    4. Ben Greiner, 2015. "Subject pool recruitment procedures: organizing experiments with ORSEE," Journal of the Economic Science Association, Springer;Economic Science Association, vol. 1(1), pages 114-125, July.
    5. Kyung Hwan Baik & Subhasish M. Chowdhury & Abhijit Ramalingam, 2021. "Group size and matching protocol in contests," Canadian Journal of Economics/Revue canadienne d'économique, John Wiley & Sons, vol. 54(4), pages 1716-1736, November.
    6. John Morgan & Henrik Orzen & Martin Sefton, 2012. "Endogenous entry in contests," Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 51(2), pages 435-463, October.
    7. Rassenti, Stephen & Reynolds, Stanley S. & Smith, Vernon L. & Szidarovszky, Ferenc, 2000. "Adaptation and convergence of behavior in repeated experimental Cournot games," Journal of Economic Behavior & Organization, Elsevier, vol. 41(2), pages 117-146, February.
    8. Jörg Oechssler & Alex Roomets & Stefan Roth, 2016. "From imitation to collusion: a replication," Journal of the Economic Science Association, Springer;Economic Science Association, vol. 2(1), pages 13-21, May.
    9. Alberto Abadie & Susan Athey & Guido W Imbens & Jeffrey M Wooldridge, 2023. "When Should You Adjust Standard Errors for Clustering?," The Quarterly Journal of Economics, President and Fellows of Harvard College, vol. 138(1), pages 1-35.
    10. Bigoni, Maria & Fort, Margherita, 2013. "Information and learning in oligopoly: An experiment," Games and Economic Behavior, Elsevier, vol. 81(C), pages 192-214.
    11. Sheremeta, Roman M., 2010. "Experimental comparison of multi-stage and one-stage contests," Games and Economic Behavior, Elsevier, vol. 68(2), pages 731-747, March.
    12. Thomas Dohmen & Armin Falk & David Huffman & Uwe Sunde & Jürgen Schupp & Gert G. Wagner, 2011. "Individual Risk Attitudes: Measurement, Determinants, And Behavioral Consequences," Journal of the European Economic Association, European Economic Association, vol. 9(3), pages 522-550, June.
    13. McKelvey Richard D. & Palfrey Thomas R., 1995. "Quantal Response Equilibria for Normal Form Games," Games and Economic Behavior, Elsevier, vol. 10(1), pages 6-38, July.
    14. Teck H. Ho & Xin Wang & Colin F. Camerer, 2008. "Individual Differences in EWA Learning with Partial Payoff Information," Economic Journal, Royal Economic Society, vol. 118(525), pages 37-59, January.
    15. Thomas Buser, 2016. "The Impact of Losing in a Competition on the Willingness to Seek Further Challenges," Management Science, INFORMS, vol. 62(12), pages 3439-3449, December.
    16. Bigoni, Maria, 2010. "What do you want to know? Information acquisition and learning in experimental Cournot games," Research in Economics, Elsevier, vol. 64(1), pages 1-17, March.
    17. Selten, Reinhard & Stoecker, Rolf, 1986. "End behavior in sequences of finite Prisoner's Dilemma supergames A learning theory approach," Journal of Economic Behavior & Organization, Elsevier, vol. 7(1), pages 47-70, March.
    18. Roth, Alvin E. & Erev, Ido, 1995. "Learning in extensive-form games: Experimental data and simple dynamic models in the intermediate term," Games and Economic Behavior, Elsevier, vol. 8(1), pages 164-212.
    19. Friedman, Daniel & Huck, Steffen & Oprea, Ryan & Weidenholzer, Simon, 2015. "From imitation to collusion: Long-run learning in a low-information environment," Journal of Economic Theory, Elsevier, vol. 155(C), pages 185-205.
    20. Shupp, Robert & Sheremeta, Roman M. & Schmidt, David & Walker, James, 2013. "Resource allocation contests: Experimental evidence," Journal of Economic Psychology, Elsevier, vol. 39(C), pages 257-267.
    21. Colin Camerer & Teck-Hua Ho, 1999. "Experience-weighted Attraction Learning in Normal Form Games," Econometrica, Econometric Society, vol. 67(4), pages 827-874, July.
    22. Mago, Shakun D. & Sheremeta, Roman M. & Yates, Andrew, 2013. "Best-of-three contest experiments: Strategic versus psychological momentum," International Journal of Industrial Organization, Elsevier, vol. 31(3), pages 287-296.
    23. Lisa Anderson & Beth Freeborn, 2010. "Varying the intensity of competition in a multiple prize rent seeking experiment," Public Choice, Springer, vol. 143(1), pages 237-254, April.
    24. Roman M. Sheremeta, 2016. "Impulsive Behavior in Competition: Testing Theories of Overbidding in Rent-Seeking Contests," Working Papers 16-21, Chapman University, Economic Science Institute.
    25. Cason, Timothy N. & Sheremeta, Roman M. & Zhang, Jingjing, 2012. "Communication and efficiency in competitive coordination games," Games and Economic Behavior, Elsevier, vol. 76(1), pages 26-43.
    26. Roman M. Sheremeta, 2013. "Overbidding And Heterogeneous Behavior In Contest Experiments," Journal of Economic Surveys, Wiley Blackwell, vol. 27(3), pages 491-514, July.
    27. Emmanuel Dechenaux & Dan Kovenock & Roman Sheremeta, 2015. "A survey of experimental research on contests, all-pay auctions and tournaments," Experimental Economics, Springer;Economic Science Association, vol. 18(4), pages 609-669, December.
    28. Fernando Vega-Redondo, 1997. "The Evolution of Walrasian Behavior," Econometrica, Econometric Society, vol. 65(2), pages 375-384, March.
    29. Lawrence Friedman, 1958. "Game-Theory Models in the Allocation of Advertising Expenditures," Operations Research, INFORMS, vol. 6(5), pages 699-709, October.
    30. Price, Curtis R. & Sheremeta, Roman M., 2011. "Endowment effects in contests," Economics Letters, Elsevier, vol. 111(3), pages 217-219, June.
    31. Klepper, Steven, 1996. "Entry, Exit, Growth, and Innovation over the Product Life Cycle," American Economic Review, American Economic Association, vol. 86(3), pages 562-583, June.
    32. Roman Sheremeta & Jingjing Zhang, 2010. "Can groups solve the problem of over-bidding in contests?," Social Choice and Welfare, Springer;The Society for Social Choice and Welfare, vol. 35(2), pages 175-197, July.
    33. Klaus Abbink & Jordi Brandts & Benedikt Herrmann & Henrik Orzen, 2010. "Intergroup Conflict and Intra-group Punishment in an Experimental Contest Game," American Economic Review, American Economic Association, vol. 100(1), pages 420-447, March.
    34. Urs Fischbacher, 2007. "z-Tree: Zurich toolbox for ready-made economic experiments," Experimental Economics, Springer;Economic Science Association, vol. 10(2), pages 171-178, June.
    35. Yves Breitmoser & Jonathan Tan & Daniel Zizzo, 2010. "Understanding perpetual R&D races," Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 44(3), pages 445-467, September.
    36. Cason, Timothy N. & Masters, William A. & Sheremeta, Roman M., 2020. "Winner-take-all and proportional-prize contests: Theory and experimental results," Journal of Economic Behavior & Organization, Elsevier, vol. 175(C), pages 314-327.
    37. Neugebauer, Tibor & Selten, Reinhard, 2006. "Individual behavior of first-price auctions: The importance of information feedback in computerized experimental markets," Games and Economic Behavior, Elsevier, vol. 54(1), pages 183-204, January.
    38. Chowdhury, Subhasish M. & Sheremeta, Roman M. & Turocy, Theodore L., 2014. "Overbidding and overspreading in rent-seeking experiments: Cost structure and prize allocation rules," Games and Economic Behavior, Elsevier, vol. 87(C), pages 224-238.
    39. Klepper, Steven, 1997. "Industry Life Cycles," Industrial and Corporate Change, Oxford University Press and the Associazione ICC, vol. 6(1), pages 145-181.
    40. Krueger, Anne O, 1974. "The Political Economy of the Rent-Seeking Society," American Economic Review, American Economic Association, vol. 64(3), pages 291-303, June.
    41. Kruse, Douglas L, 1992. "Profit Sharing and Productivity: Microeconomic Evidence from the United States," Economic Journal, Royal Economic Society, vol. 102(410), pages 24-36, January.
    42. Gunnthorsdottir, Anna & Rapoport, Amnon, 2006. "Embedding social dilemmas in intergroup competition reduces free-riding," Organizational Behavior and Human Decision Processes, Elsevier, vol. 101(2), pages 184-199, November.
    43. Nicolas Treich, 2010. "Risk-aversion and prudence in rent-seeking games," Public Choice, Springer, vol. 145(3), pages 339-349, December.
    44. Stefan Szymanski, 2003. "The Assessment: The Economics of Sport," Oxford Review of Economic Policy, Oxford University Press and Oxford Review of Economic Policy Limited, vol. 19(4), pages 467-477, Winter.
    45. Roman M. Sheremeta, 2011. "Contest Design: An Experimental Investigation," Economic Inquiry, Western Economic Association International, vol. 49(2), pages 573-590, April.
    46. Xiaojing Kong, 2008. "Loss Aversion and Rent-Seeking: An Experimental Study," Discussion Papers 2008-13, The Centre for Decision Research and Experimental Economics, School of Economics, University of Nottingham.
    47. Cason, Timothy N. & Masters, William A. & Sheremeta, Roman M., 2010. "Entry into winner-take-all and proportional-prize contests: An experimental study," Journal of Public Economics, Elsevier, vol. 94(9-10), pages 604-611, October.
    48. Lim, Wooyoung & Matros, Alexander & Turocy, Theodore L., 2014. "Bounded rationality and group size in Tullock contests: Experimental evidence," Journal of Economic Behavior & Organization, Elsevier, vol. 99(C), pages 155-167.
    49. Curtis R. Price & Roman M. Sheremeta, 2015. "Endowment Origin, Demographic Effects, and Individual Preferences in Contests," Journal of Economics & Management Strategy, Wiley Blackwell, vol. 24(3), pages 597-619, September.
    50. Emel Filiz-Ozbay & Erkut Y. Ozbay, 2007. "Auctions with Anticipated Regret: Theory and Experiment," American Economic Review, American Economic Association, vol. 97(4), pages 1407-1418, September.
    51. Pamela Schmitt & Robert Shupp & Kurtis Swope & John Cadigan, 2004. "Multi-period rent-seeking contests with carryover: Theory and experimental evidence," Economics of Governance, Springer, vol. 5(3), pages 187-211, November.
    52. Gort, Michael & Klepper, Steven, 1982. "Time Paths in the Diffusion of Product Innovations," Economic Journal, Royal Economic Society, vol. 92(367), pages 630-653, September.
    53. Boyan Jovanovic & Yaw Nyarko, 1995. "A Bayesian Learning Model Fitted to a Variety of Empirical Learning Curves," Brookings Papers on Economic Activity, Economic Studies Program, The Brookings Institution, vol. 26(1995 Micr), pages 247-305.
    54. Huck, Steffen & Normann, Hans-Theo & Oechssler, Jorg, 1999. "Learning in Cournot Oligopoly--An Experiment," Economic Journal, Royal Economic Society, vol. 109(454), pages 80-95, March.
    55. Konrad, Kai A & Schlesinger, Harris, 1997. "Risk Aversion in Rent-Seeking and Rent-Augmenting Games," Economic Journal, Royal Economic Society, vol. 107(445), pages 1671-1683, November.
    56. TeckH. Ho & Xin Wang & ColinF. Camerer, 2008. "Individual Differences in EWA Learning with Partial Payoff Information," Economic Journal, Royal Economic Society, vol. 118(525), pages 37-59, January.
    57. Lisa Anderson & Beth Freeborn, 2010. "Erratum to: Varying the intensity of competition in a multiple prize rent seeking experiment," Public Choice, Springer, vol. 143(1), pages 255-256, April.
    58. Konrad, Kai A., 2009. "Strategy and Dynamics in Contests," OUP Catalogue, Oxford University Press, number 9780199549603, Decembrie.
    59. Huck, Steffen & Normann, Hans-Theo & Oechssler, Jorg, 2004. "Two are few and four are many: number effects in experimental oligopolies," Journal of Economic Behavior & Organization, Elsevier, vol. 53(4), pages 435-446, April.
    60. Alós-Ferrer, Carlos & Ritschel, Alexander, 2018. "The reinforcement heuristic in normal form games," Journal of Economic Behavior & Organization, Elsevier, vol. 152(C), pages 224-234.
    61. Subhasish M. Chowdhury & Joo Young Jeon & Abhijit Ramalingam, 2018. "Property Rights And Loss Aversion In Contests," Economic Inquiry, Western Economic Association International, vol. 56(3), pages 1492-1511, July.
    62. Christoph Engel, 2007. "How Much Collusion? A Meta-Analysis Of Oligopoly Experiments," Journal of Competition Law and Economics, Oxford University Press, vol. 3(4), pages 491-549.
    63. Jovanovic, Boyan, 1982. "Selection and the Evolution of Industry," Econometrica, Econometric Society, vol. 50(3), pages 649-670, May.
    64. Skaperdas, Stergios & Gan, Li, 1995. "Risk Aversion in Contests," Economic Journal, Royal Economic Society, vol. 105(431), pages 951-962, July.
    65. Christopher Harris & John Vickers, 1985. "Perfect Equilibrium in a Model of a Race," The Review of Economic Studies, Review of Economic Studies Ltd, vol. 52(2), pages 193-209.
    66. Edward Millner & Michael Pratt, 1989. "An experimental investigation of efficient rent-seeking," Public Choice, Springer, vol. 62(2), pages 139-151, August.
    67. Hopkins, Michael M. & Martin, Paul A. & Nightingale, Paul & Kraft, Alison & Mahdi, Surya, 2007. "The myth of the biotech revolution: An assessment of technological, clinical and organisational change," Research Policy, Elsevier, vol. 36(4), pages 566-589, May.
    68. Boosey, Luke & Brookins, Philip & Ryvkin, Dmitry, 2017. "Contests with group size uncertainty: Experimental evidence," Games and Economic Behavior, Elsevier, vol. 105(C), pages 212-229.
    69. Millner, Edward L & Pratt, Michael D, 1991. "Risk Aversion and Rent-Seeking: An Extension and Some Experimental Evidence," Public Choice, Springer, vol. 69(1), pages 81-92, February.
    70. Schram, Arthur & Sonnemans, Joep, 1996. "Voter Turnout as a Participation Game: An Experimental Investigation," International Journal of Game Theory, Springer;Game Theory Society, vol. 25(3), pages 385-406.
    71. Anderson, Lisa R & Stafford, Sarah L, 2003. "An Experimental Analysis of Rent Seeking under Varying Competitive Conditions," Public Choice, Springer, vol. 115(1-2), pages 199-216, April.
    72. Fudenberg, Drew & Gilbert, Richard & Stiglitz, Joseph & Tirole, Jean, 1983. "Preemption, leapfrogging and competition in patent races," European Economic Review, Elsevier, vol. 22(1), pages 3-31, June.
    73. Garvin, Susan & Kagel, John H., 1994. "Learning in common value auctions: Some initial observations," Journal of Economic Behavior & Organization, Elsevier, vol. 25(3), pages 351-372, December.
    74. Snyder, James M, 1989. "Election Goals and the Allocation of Campaign Resources," Econometrica, Econometric Society, vol. 57(3), pages 637-660, May.
    75. Camerer, Colin F. & Ho, Teck-Hua & Chong, Juin-Kuan, 2002. "Sophisticated Experience-Weighted Attraction Learning and Strategic Teaching in Repeated Games," Journal of Economic Theory, Elsevier, vol. 104(1), pages 137-188, May.
    76. Levin, Andrew & Lin, Chien-Fu & James Chu, Chia-Shang, 2002. "Unit root tests in panel data: asymptotic and finite-sample properties," Journal of Econometrics, Elsevier, vol. 108(1), pages 1-24, May.
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