IDEAS home Printed from
   My bibliography  Save this paper

Estimating market power in homogenous product markets using a composed error model: application to the California electricity market


  • Orea, L.
  • Steinbuks, J.


This study contributes to the literature on estimating market power in homogenous product markets. We estimate a composed error model, where the stochastic part of the firm’s pricing equation is formed by two random variables: the traditional error term, capturing random shocks, and a random conduct term, which measures the degree of market power. Treating firms’ conduct as a random parameter helps solving the issue that the conduct parameter can vary between firms and within firms over time. The empirical results from the California wholesale electricity market suggest that realization of market power varies over both time and firms, and reject the assumption of a common conduct parameter for all firms. Notwithstanding these differences, the estimated firm-level values of the conduct parameter are closer to Cournot than to static collusion across all specifications. For some firms, the potential for realization of the market power unilaterally is associated with lower values of the conduct parameter.

Suggested Citation

  • Orea, L. & Steinbuks, J., 2012. "Estimating market power in homogenous product markets using a composed error model: application to the California electricity market," Cambridge Working Papers in Economics 1220, Faculty of Economics, University of Cambridge.
  • Handle: RePEc:cam:camdae:1220

    Download full text from publisher

    File URL:
    Download Restriction: no

    Other versions of this item:

    References listed on IDEAS

    1. Fabra, Natalia & Toro, Juan, 2005. "Price wars and collusion in the Spanish electricity market," International Journal of Industrial Organization, Elsevier, vol. 23(3-4), pages 155-181, April.
    2. Severin Boreinstein & Andrea Shepard, 1996. "Dynamic Pricing in Retail Gasoline Markets," RAND Journal of Economics, The RAND Corporation, vol. 27(3), pages 429-451, Autumn.
    3. Christopher Knittel & Catherine Wolfram & James Bushnell & Severin Borenstein, 2006. "Inefficiencies and Market Power in Financial Arbitrage: A Study of California?s Electricity Markets," Working Papers 630, University of California, Davis, Department of Economics.
    4. Brander, James A. & Zhang, Anming, 1993. "Dynamic oligopoly behaviour in the airline industry," International Journal of Industrial Organization, Elsevier, vol. 11(3), pages 407-435, September.
    5. Antonio Alvarez & Christine Amsler & Luis Orea & Peter Schmidt, 2006. "Interpreting and Testing the Scaling Property in Models where Inefficiency Depends on Firm Characteristics," Journal of Productivity Analysis, Springer, vol. 25(3), pages 201-212, June.
    6. Grigorios Emvalomatis & Spiro E. Stefanou & Alfons Oude Lansink, 2010. "A Reduced-Form Model for Dynamic Efficiency Measurement: Application to Dairy Farms in Germany and The Netherlands," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 93(1), pages 161-174.
    7. Severin Borenstein & James Bushnell & Christopher R. Knittel & Catherine Wolfram, 2008. "INEFFICIENCIES AND MARKET POWER IN FINANCIAL ARBITRAGE: A STUDY OF CALIFORNIA'S ELECTRICITY MARKETS -super-," Journal of Industrial Economics, Wiley Blackwell, vol. 56(2), pages 347-378, June.
    8. Abreu, Dilip & Pearce, David & Stacchetti, Ennio, 1986. "Optimal cartel equilibria with imperfect monitoring," Journal of Economic Theory, Elsevier, vol. 39(1), pages 251-269, June.
    9. Severin Borenstein, 2002. "The Trouble With Electricity Markets: Understanding California's Restructuring Disaster," Journal of Economic Perspectives, American Economic Association, vol. 16(1), pages 191-211, Winter.
    10. Bresnahan, Timothy F., 1989. "Empirical studies of industries with market power," Handbook of Industrial Organization,in: R. Schmalensee & R. Willig (ed.), Handbook of Industrial Organization, edition 1, volume 2, chapter 17, pages 1011-1057 Elsevier.
    11. Karen Clay & Werner Troesken, 2003. "Further Tests of Static Oligopoly Models: Whiskey, 1882-1898," Journal of Industrial Economics, Wiley Blackwell, vol. 51(2), pages 151-166, June.
    12. Borenstein, Severin & Rose, Nancy L, 1994. "Competition and Price Dispersion in the U.S. Airline Industry," Journal of Political Economy, University of Chicago Press, vol. 102(4), pages 653-683, August.
    13. Appelbaum, Elie, 1982. "The estimation of the degree of oligopoly power," Journal of Econometrics, Elsevier, vol. 19(2-3), pages 287-299, August.
    14. Corts, Kenneth S., 1998. "Conduct parameters and the measurement of market power," Journal of Econometrics, Elsevier, vol. 88(2), pages 227-250, November.
    Full references (including those not matched with items on IDEAS)


    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.

    Cited by:

    1. Sickles, Robin C. & Hao, Jiaqi & Shang, Chenjun, 2015. "Panel Data and Productivity Measurement," Working Papers 15-018, Rice University, Department of Economics.
    2. Chiara Lo Prete and Benjamin F. Hobbs, 2015. "Market power in power markets: an analysis of residual demand curves in Californias day-ahead energy market (1998-2000)," The Energy Journal, International Association for Energy Economics, vol. 0(Number 2).
    3. Sapio, Alessandro & Spagnolo, Nicola, 2016. "Price regimes in an energy island: Tacit collusion vs. cost and network explanations," Energy Economics, Elsevier, vol. 55(C), pages 157-172.

    More about this item


    market power; random conduct parameter; composed error model; asymmetric distributions; California electricity market;

    JEL classification:

    • C34 - Mathematical and Quantitative Methods - - Multiple or Simultaneous Equation Models; Multiple Variables - - - Truncated and Censored Models; Switching Regression Models
    • C51 - Mathematical and Quantitative Methods - - Econometric Modeling - - - Model Construction and Estimation
    • L13 - Industrial Organization - - Market Structure, Firm Strategy, and Market Performance - - - Oligopoly and Other Imperfect Markets
    • L94 - Industrial Organization - - Industry Studies: Transportation and Utilities - - - Electric Utilities

    NEP fields

    This paper has been announced in the following NEP Reports:


    Access and download statistics


    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:cam:camdae:1220. See general information about how to correct material in RePEc.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Jake Dyer). General contact details of provider: .

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service hosted by the Research Division of the Federal Reserve Bank of St. Louis . RePEc uses bibliographic data supplied by the respective publishers.