The Lerner Index as a Measure of Market Power of U.S. Credit Unions in the Absence of Profit Maximization


  • Tobias Vervliet University of Groningen


This paper explores the theoretical implications of a change in the behavioral assumptions of the Lerner index in the case of U.S. credit unions which do not operate under profit maximization. Despite the finding that the Lerner index underestimates the actual degree of market power in this non standard case, the value found for credit unions is significantly higher than for commercial banks. In other words, credit unions behave relatively monopolistically.


Baumol, William J and David F Bradford (1970).

Optimal Departures from Marginal Cost Pricing.

The American Economic Review, 265–283.

Elzinga, Kenneth G and David E Mills (2011).

The Lerner Index of Monopoly Power: Origins

and Uses. The American Economic Review,


Emmons,William R and Frank A Schmid (2000).

Bank Competition and Concentration: Do

Credit Unions Matter? Federal Reserve Bank

of St. Louis Review 82(May/June 2000).

Froman, Lewis A (1935). Credit Unions. Journal

of Business of the University of Chicago, 284–

Koetter, Michael, James W Kolari, and Laura

Spierdijk (2012). Enjoying the Quiet Life under

Deregulation? Evidence from Adjusted

Lerner Indices for US Banks. Review of Economics

and Statistics, 462–480.

Lerner, Abba P (1934). The Concept of Monopoly

and the Measurement of Monopoly Power. The

Review of Economic Studies, 157–175.

Murray, John D and Robert W White (1980).

Economies of Scale and Deposit-Taking Financial

Institutions in Canada: Study of British

Columbia Credit Unions. Journal of Money,

Credit and Banking, 58–70.

Shaffer, Sherrill and Laura Spierdijk (2013).

Duopoly Conduct and the Panzar-Rosse Revenue


Smith, Donald J, Thomas F Cargill, and Robert A

Meyer (1981). Credit Unions: An Economic

Theory of a Credit Union. The Journal of Finance,


Spierdijk, Laura and Michalis Zaouras (2014, December).

The Lerner Index and Revenue Maximization

Subject With a Minimum-Profit Constraint.

Working paper University of Groningen.

Taylor, Ryland A (1971). The Credit Union as a

Cooperative Institution. Review of Social Economy,





How to Cite

Vervliet, T. (2015). The Lerner Index as a Measure of Market Power of U.S. Credit Unions in the Absence of Profit Maximization. Student Undergraduate Research E-Journal!, 1. Retrieved from



Economics & Social Sciences