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The Measurement of Voting Power and its use to inform the design of international organisations


This research focuses on the measurement of voting power and its use in the analysisof international organisations. The work is both methodological and applied. Voting power analysis is useful for understanding power in organizations whose constitutions employ weighted voting, such as the Bretton Woods institutions. These bodies use block voting systems that give countries unequal power according to a formula designed to reflect their demographic or economic importance. Such weighted voting systems however can have surprising properties and a country’Ĵs real constitutional power can differ from what is intended. This project has looked at methods for addressing this problem using voting power indices. It has made advances in (1) methods of computing power indices, (2) the properties of power indices as measures of power and (3) the use of power indices in helping to answer the normative question of what the voting weights ought to be in order to achieve the desired degree of inequality in voting power within an organization.

The methods have been applied to the governing body and the executive board of the IMF. The research shows that the system of weighted voting used in the constitution of that body tends to further disenfranchise the poor countries even more than is commonly supposed.

The methods have also been used to study the system of qualified majority voting in the EU Council of Ministers after the Nice Treaty.

Further work on power in the IMF and World Bank will focus on three aspects: (i) an analysis of power within the constituency structure of the Executive Board. There is evidence that the present constituency structure works to enhance the power of the developed and/or creditor countries; weighted voting has an additional effect which might work to reinforce that effect and further disenfranchise the poor. (ii) The determination of quotas. I intend to investigate the power implications of the different bases on which quotas are determined. (iii) The representation of the developing and/or debtor countries.

Letter published in The Guardian July 18, 2002

Why the IMF remains undemocratic

Graham Hacche (Letters, July 16) says the IMF is democratically accountable through its board of governors which consists of one representative from each member country. Each country's voting power reflects its "quotas", which is broadly determined by its economic size and financial contributions.

Even accepting this definition of accountability, the IMF constitution does not implement it. In systems of weighted voting - where each member casts all its votes as a bloc - a member's voting power is different from its weighted votes. Research at Warwick University, just published, shows that the system of weighted voting leads to the over concentration of power in the hands of the US. For example, the US with 17.55% of the votes has 8.86 times more weight than India, with 1.98% of the votes. But the voting power of the US - how frequently it could decide an issue if a vote were taken - is found to be 14.11 times that of India.

Dennis Leech University of Warwick



Articles already published

Voting Power in the Governance of the International Monetary Fund, Annals of Operations Research, vol.109, January 2002, pp373-395.

Designing the Voting System for the EU Council of Ministers, Public Choice, vol. 113, 2002, pp. 437-464. Full Document

An Empirical Comparison of the Performance of Classical Power Indices , Political Studies, vol.50, No.1, February 2002, pp. 1-22.

Forthcoming articles

"Computing Power Indices for Large Voting Games", Warwick Economic Research Papers, Number 579. Forthcoming in Management Science.

"Power Indices as an Aid to Institutional Design: the Generalised Apportionment Problem", Warwick Economic Research Papers, Number 648 to be published in the Yearbook on New Political Economy, edited by M. Holler, H.Kliemt, D. Schmidtchen and M. Streit.

"Qualified Majority Voting: The Effect of the Quota", Revised September 2002, Mimeo, CPNSS, LSE. (with Moshˆ© Machover)., to be published in the Yearbook on New Political Economy, edited by M. Holler, H.Kliemt, D. Schmidtchen and M. Streit.

Relevant Working Papers in the WERP series

"Computation of Power Indices" (Warwick Economic Research Paper no. 644, July 2002).

"The Use of Coleman's Power Indices to Inform the Choice of Voting Rule with Reference to the IMF Governing Body and the EU Council of Ministers" (Warwick Economic Research Papers no 645 July 2002)

Relevant Conference Presentations (October 2001- September 2002)

Presenter: Dennis Leech "Designing the Voting System for the European Council", Public Choice Society Meeting, San Diego, California, March 2002, also at 5th Annual Workshop in Applied Game Theory, Institute of Socioeconomics, University of Hamburg, 7-8 December, 2001.

Presenter: Dennis Leech The Use of Colemans Power Indices to inform the choice of voting rule with reference to the EU Council of Ministers, presented at the workshop Modelling the European Decision Making, July 11-14, San Sebastian, Spain.

Presenter: Dennis Leech Advanced lectures on Computing Power Indices, at the Summer School, EU Decision Making: Assessment and Design of Procedures, July 8th-11th 2002, San Sebastian Spain (organised by Federico Valenciano, University of the Basque Country).

Presenter: Moshe Machover The Effect of the Quota in a Weighted Voting Body with a Given Distribution of Voting Power: an Application to the 27-Member CM, to be presented to the Workshops Modelling the European Decision Making, July 11-14, San Sebastian, Spain and Saarbrˆºcken Conference On European Governance (organised by Dieter Schmidtchen), 10.-12 Oct. 2002, with Moshˆ© Machover.

Presenter: Dennis Leech Power Indices as an Aid to Institutional Design, presented at the Workshop Voting Power Analysis, August 9-11th, Voting Power and Procedures Programme, CPNSS, London School of Economics, also at Saarbrˆºcken Conference On European Governance (organised by Dieter Schmidtchen), 10.-12 Oct. 2002.