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Supply Function Equilibria: Step functions and continuous representations

Author

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  • Pär Holmberg

    (Research Institute of Industrial Economics, Stockholm)

  • David Newbery

    (Faculty of Economics, University of Cambridge)

  • Daniel Ralph

    (Judge Business School, University of Cambridge)

Abstract

In most wholesale electricity markets generators must submit stepfunction offers of supply to a uniform price auction, and the market is cleared at the price of the most expensive offer needed to meet realised demand. Such markets can most elegantly be modelled as the purestrategy, Nash Equilibrium of continuous supply functions, in which each supplier has a unique profit maximising choice of supply function given the choices of other suppliers. Critics argue that the discreteness and discontinuity of the required steps can rule out pure-strategy equilibria and may result in price instability. This paper argues that if prices must be selected from a finite set the resulting step function converges to the continuous supply function as the number of steps increases, reconciling the apparently very disparate approaches to modelling electricity markets.
(This abstract was borrowed from another version of this item.)

Suggested Citation

  • Pär Holmberg & David Newbery & Daniel Ralph, 2008. "Supply Function Equilibria: Step functions and continuous representations," Working Papers EPRG 0829, Energy Policy Research Group, Cambridge Judge Business School, University of Cambridge.
  • Handle: RePEc:enp:wpaper:eprg0829
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    1. Natalia Fabra & Nils‐Henrik Fehr & David Harbord, 2006. "Designing electricity auctions," RAND Journal of Economics, RAND Corporation, vol. 37(1), pages 23-46, March.
    2. Jakub Kastl, 2011. "Discrete Bids and Empirical Inference in Divisible Good Auctions," The Review of Economic Studies, Review of Economic Studies Ltd, vol. 78(3), pages 974-1014.
    3. Natalia Fabra & Nils-Henrik M. von der Fehr & David Harbord, 2006. "Designing Electricity Auctions," RAND Journal of Economics, The RAND Corporation, vol. 37(1), pages 23-46, Spring.
    4. Frank A. Wolak, 2007. "Quantifying the supply-side benefits from forward contracting in wholesale electricity markets," Journal of Applied Econometrics, John Wiley & Sons, Ltd., vol. 22(7), pages 1179-1209.
    5. David McAdams, 2003. "Isotone Equilibrium in Games of Incomplete Information," Econometrica, Econometric Society, vol. 71(4), pages 1191-1214, July.
    6. E. J. Anderson & A. B. Philpott, 2002. "Using Supply Functions for Offering Generation into an Electricity Market," Operations Research, INFORMS, vol. 50(3), pages 477-489, June.
    7. Robert Wilson, 1979. "Auctions of Shares," The Quarterly Journal of Economics, President and Fellows of Harvard College, vol. 93(4), pages 675-689.
    8. Robert Wilson, 2008. "Supply Function Equilibrium in a Constrained Transmission System," Operations Research, INFORMS, vol. 56(2), pages 369-382, April.
    9. Edward J. Anderson & Xinmin Hu, 2008. "Finding Supply Function Equilibria with Asymmetric Firms," Operations Research, INFORMS, vol. 56(3), pages 697-711, June.
    10. Unknown, 2005. "Forward," 2005 Conference: Slovenia in the EU - Challenges for Agriculture, Food Science and Rural Affairs, November 10-11, 2005, Moravske Toplice, Slovenia 183804, Slovenian Association of Agricultural Economists (DAES).
    11. Frank Wolak, 2000. "An Empirical Analysis of the Impact of Hedge Contracts on Bidding Behavior in a Competitive Electricity Market," International Economic Journal, Taylor & Francis Journals, vol. 14(2), pages 1-39.
    12. Green, Richard J & Newbery, David M, 1992. "Competition in the British Electricity Spot Market," Journal of Political Economy, University of Chicago Press, vol. 100(5), pages 929-953, October.
    13. Holmberg, Pär & Newbery, David & Ralph, Daniel, 2013. "Supply function equilibria: Step functions and continuous representations," Journal of Economic Theory, Elsevier, vol. 148(4), pages 1509-1551.
    14. Holmberg, Pär, 2009. "Numerical calculation of an asymmetric supply function equilibrium with capacity constraints," European Journal of Operational Research, Elsevier, vol. 199(1), pages 285-295, November.
    15. Holmberg, Par, 2008. "Unique supply function equilibrium with capacity constraints," Energy Economics, Elsevier, vol. 30(1), pages 148-172, January.
    16. Supatgiat, Chonawee & Zhang, Rachel Q & Birge, John R, 2001. "Equilibrium Values in a Competitive Power Exchange Market," Computational Economics, Springer;Society for Computational Economics, vol. 17(1), pages 93-121, February.
    17. Parisio, Lucia & Bosco, Bruno, 2003. "Market Power and the Power Market: Multi-unit Bidding and (In)Efficiency in Electricity Auctions," International Tax and Public Finance, Springer;International Institute of Public Finance, vol. 10(4), pages 377-401, August.
    18. David M. Newbery, 1998. "Competition, Contracts, and Entry in the Electricity Spot Market," RAND Journal of Economics, The RAND Corporation, vol. 29(4), pages 726-749, Winter.
    19. Ilan Kremer & Kjell G. Nyborg, 2004. "Divisible-Good Auctions: The Role of Allocation Rules," RAND Journal of Economics, The RAND Corporation, vol. 35(1), pages 147-159, Spring.
    20. Green, Richard J, 1996. "Increasing Competition in the British Electricity Spot Market," Journal of Industrial Economics, Wiley Blackwell, vol. 44(2), pages 205-216, June.
    21. Andrew Sweeting, 2007. "Market Power In The England And Wales Wholesale Electricity Market 1995-2000," Economic Journal, Royal Economic Society, vol. 117(520), pages 654-685, April.
    22. Genc, Talat S. & Reynolds, Stanley S., 2011. "Supply function equilibria with capacity constraints and pivotal suppliers," International Journal of Industrial Organization, Elsevier, vol. 29(4), pages 432-442, July.
    23. Anderson, Edward, 2011. "Supply Function Equilibria Always Exist," Working Papers 04/2011, University of Sydney Business School, Discipline of Business Analytics.
    24. Par Holmberg, 2007. "Supply Function Equilibrium with Asymmetric Capacities and Constant Marginal Costs," The Energy Journal, International Association for Energy Economics, vol. 0(Number 2), pages 55-82.
    25. Ramteen Sioshansi & Shmuel Oren, 2007. "How good are supply function equilibrium models: an empirical analysis of the ERCOT balancing market," Journal of Regulatory Economics, Springer, vol. 31(1), pages 1-35, February.
    26. Partha Dasgupta & Eric Maskin, 1986. "The Existence of Equilibrium in Discontinuous Economic Games, I: Theory," The Review of Economic Studies, Review of Economic Studies Ltd, vol. 53(1), pages 1-26.
    27. E. J. Anderson & H. Xu, 2004. "Nash equilibria in electricity markets with discrete prices," Mathematical Methods of Operations Research, Springer;Gesellschaft für Operations Research (GOR);Nederlands Genootschap voor Besliskunde (NGB), vol. 60(2), pages 215-238, October.
    28. Philip J. Reny, 1999. "On the Existence of Pure and Mixed Strategy Nash Equilibria in Discontinuous Games," Econometrica, Econometric Society, vol. 67(5), pages 1029-1056, September.
    29. Klemperer, Paul D & Meyer, Margaret A, 1989. "Supply Function Equilibria in Oligopoly under Uncertainty," Econometrica, Econometric Society, vol. 57(6), pages 1243-1277, November.
    30. Ilan Kremer, 2004. "Underpricing and Market Power in Uniform Price Auctions," The Review of Financial Studies, Society for Financial Studies, vol. 17(3), pages 849-877.
    31. David M. Newbery, 1995. "Power Markets and Market Power," The Energy Journal, International Association for Energy Economics, vol. 0(Number 3), pages 39-66.
    32. Ali Hortaçsu & Steven L. Puller, 2008. "Understanding strategic bidding in multi‐unit auctions: a case study of the Texas electricity spot market," RAND Journal of Economics, RAND Corporation, vol. 39(1), pages 86-114, March.
    33. Bagh, Adib, 2010. "Variational convergence: Approximation and existence of equilibria in discontinuous games," Journal of Economic Theory, Elsevier, vol. 145(3), pages 1244-1268, May.
    34. Ross Baldick & Ryan Grant & Edward Kahn, 2004. "Theory and Application of Linear Supply Function Equilibrium in Electricity Markets," Journal of Regulatory Economics, Springer, vol. 25(2), pages 143-167, March.
    35. von der Fehr, Nils-Henrik Morch & Harbord, David, 1993. "Spot Market Competition in the UK Electricity Industry," Economic Journal, Royal Economic Society, vol. 103(418), pages 531-546, May.
    36. Aleksandr Rudkevich & Max Duckworth & Richard Rosen, 1998. "Modeling Electricity Pricing in a Deregulated Generation Industry: The Potential for Oligopoly Pricing in a Poolco," The Energy Journal, International Association for Energy Economics, vol. 0(Number 3), pages 19-48.
    37. Leo K. Simon, 1987. "Games with Discontinuous Payoffs," The Review of Economic Studies, Review of Economic Studies Ltd, vol. 54(4), pages 569-597.
    38. Kastl, Jakub, 2012. "On the properties of equilibria in private value divisible good auctions with constrained bidding," Journal of Mathematical Economics, Elsevier, vol. 48(6), pages 339-352.
    39. Gatti, J.R.J., 2005. "A Note on the Existence of Nash Equilibrium in Games with Discontinuous Payoffs," Cambridge Working Papers in Economics 0510, Faculty of Economics, University of Cambridge.
    40. Frank A. Wolak, 2001. "Identification and Estimation of Cost Functions Using Observed Bid Data: An Application to Electricity Markets," NBER Working Papers 8191, National Bureau of Economic Research, Inc.
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    More about this item

    Keywords

    Auctions; supply function equilibria; convergence of step-functions; electricity markets;
    All these keywords.

    JEL classification:

    • D43 - Microeconomics - - Market Structure, Pricing, and Design - - - Oligopoly and Other Forms of Market Imperfection
    • D44 - Microeconomics - - Market Structure, Pricing, and Design - - - Auctions
    • C62 - Mathematical and Quantitative Methods - - Mathematical Methods; Programming Models; Mathematical and Simulation Modeling - - - Existence and Stability Conditions of Equilibrium
    • L94 - Industrial Organization - - Industry Studies: Transportation and Utilities - - - Electric Utilities

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