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Qualified majority voting : the effect of the quota

Leech, Dennis and Machover, Moshé (2003) Qualified majority voting : the effect of the quota. In: Holler, M. J., Kliemt, H., Schmidtchen, D. and Streit, M. E., (eds.) European Governance. Jahrbuch Für Neue Politische Ökonomie. Mohr Siebeck (Firm), Tübingen, Germany, pp. 127-143. ISBN 3161482190

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We explore the effect of various values of the quota of QMV in an enlarged, 27-member Council of Ministers of the EU. In order to isolate the effect of the quota q, we assume, for all values of q, an ‘equitable’ distribution of voting power, according to Penrose’s Square-Root Rule. For each value of q from q = 51% to near 100% of the total weight, we compute the system of weights that produces an equitable distribution of voting power. This enables us to examine the effect of q (with an equitable distribution of power) on various quantities, including: the voting power of each member; the blocking power (Coleman’s ‘power to prevent action’) of each member; the sensitivity of the decision rule; Coleman’s parameter A (‘ability of the collectivity to act’); the mean majority deficit. A particularly interesting phenomenon is the effect of varying q on the weight of each member.

Item Type: Book Section
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Additional Information: The authors gratefully acknowledge that work on this paper was partly supported by the Leverhulme Trust (Grant F/07-004m). Published 2003 © Moshé Machover. LSE has developed LSE Research Online so that users may access research output of the School. Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Users may download and/or print one copy of any article(s) in LSE Research Online to facilitate their private study or for non-commercial research. You may not engage in further distribution of the material or use it for any profit-making activities or any commercial gain. You may freely distribute the URL ( of the LSE Research Online website.
Divisions: LSE
Subjects: J Political Science > JC Political theory
Date Deposited: 22 Dec 2005
Last Modified: 15 Sep 2023 09:06

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