How Do Firms Exercise Unilateral Market Power? Evidence from a Bid-Based Wholesale Electricity Market
This paper uses the framework in Wolak (2003a,b and 2007) and data on half-hourly offer curves and market-clearing prices and quantities from the New Zealand wholesale electricity market over the period January 1, 2001 to June 30, 2007 to characterize how the four large suppliers in this imperfectly competitive industry exercise market power. To accomplish this we introduce half-hourly measures of the firm-level ability and incentive of an individual supplier to exercise unilateral market power that are derived from a simplified model of expected profit-maximizing offer behaviour in a multi-unit auction market. We then show that half-hourly market-clearing prices are highly correlated with the half-hourly values of the firm-level and firm-average measures of both the ability and incentive of the four large suppliers in New Zealand to exercise market power. We then present evidence consistent with the view that this increasing relationship between the ability or incentive of individual suppliers to exercise market power and higher market-clearing prices is caused by the four large suppliers submitting higher offer prices when they have a greater ability or incentive to exercise unilateral market power. We show that after controlling for changes in input fossil fuel prices and other factors that impact the opportunity cost of producing electricity during that half hour, each of the four suppliers submits a higher offer price into the wholesale market when it has a greater ability or incentive to exercise unilateral market power. To strengthen the case that this increasing relationship between market prices and the ability and incentive of each of the suppliers to exercise unilateral market power is actually caused by the four large suppliers exercising unilateral market power by changing their offer prices in response to their ability and incentive to exercise market power, we also perform a test of the implications of the null hypothesis that the four large suppliers behave as if they had no ability to exercise market power. We find strong evidence against this null hypothesis and instead find that these hypothesis testing results are consistent with the perspective that these suppliers are exercising all available unilateral market power.Classification-JEL:
|Date of creation:||15 Jul 2009|
|Date of revision:|
|Contact details of provider:|| Postal: |
Web page: http://www.eui.eu/RSCAS/
More information through EDIRC
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:
- Nevo, Aviv, 1998.
"Measuring Market Power in the Ready-To-Eat Cereal Industry,"
25164, University of Connecticut, Food Marketing Policy Center.
- Nevo, Aviv, 2001. "Measuring Market Power in the Ready-to-Eat Cereal Industry," Econometrica, Econometric Society, vol. 69(2), pages 307-42, March.
- Nevo, Aviv, 1998. "Measuring Market Power in the Ready-To-Eat Cereal Industry," Food Marketing Policy Center Research Reports 037, University of Connecticut, Department of Agricultural and Resource Economics, Charles J. Zwick Center for Food and Resource Policy.
- Aviv Nevo, 1998. "Measuring Market Power in the Ready-to-Eat Cereal Industry," NBER Working Papers 6387, National Bureau of Economic Research, Inc.
- Nevo, Aviv, 1999. "Measuring Market Power in the Ready-to-Eat Cereal Industry," Competition Policy Center, Working Paper Series qt7cm5p858, Competition Policy Center, Institute for Business and Economic Research, UC Berkeley.
- Aviv Nevo, 2003. "Measuring Market Power in the Ready-to-Eat Cereal Industry," Microeconomics 0303006, EconWPA.
- Goldberg, Pinelopi Koujianou, 1995. "Product Differentiation and Oligopoly in International Markets: The Case of the U.S. Automobile Industry," Econometrica, Econometric Society, vol. 63(4), pages 891-951, July.
- 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.
- Bresnahan, Timothy F., 1981. "Departures from marginal-cost pricing in the American automobile industry : Estimates for 1977-1978," Journal of Econometrics, Elsevier, vol. 17(2), pages 201-227, November.
- Rosse, James N, 1970. "Estimating Cost Function Parameters without Using Cost Data: Illustrated Methodology," Econometrica, Econometric Society, vol. 38(2), pages 256-75, March.
- Robert H. Porter, 1983. "A Study of Cartel Stability: The Joint Executive Committee, 1880-1886," Bell Journal of Economics, The RAND Corporation, vol. 14(2), pages 301-314, Autumn.
- Frank A. Wolak, 2003. "Measuring Unilateral Market Power in Wholesale Electricity Markets: The California Market, 1998–2000," American Economic Review, American Economic Association, vol. 93(2), pages 425-430, May.
- Berry, Steven & Levinsohn, James & Pakes, Ariel, 1995. "Automobile Prices in Market Equilibrium," Econometrica, Econometric Society, vol. 63(4), pages 841-90, July.
When requesting a correction, please mention this item's handle: RePEc:rsc:rsceui:2009/36. 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: (RSCAS web unit)
If references are entirely missing, you can add them using this form.