Dennis Leech

• PhD
• Professor Emeritus at University of Warwick

It is increasingly common to statistically compare macroscopic brain maps to assess how spatially similar they are. Due to the presence of spatial autocorrelation, statistical inference can be challenging; to address this, random permutation approaches based on null models are widely used. Here, we show how that the presence of heterogeneity in the...

The weighted voting system used by the International Monetary Fund in its board of governors and executive creates problems of democratic legitimacy because each member’s influence over decisions taken by vote, that is its voting power, is not in general in proportion to its voting weight, that is, the number of votes it casts. This paper uses voti...

Many voting bodies are constituted on a principle of accountability whereby a member’s influence is intended to be a reflection of a measure of size such as financial contribution or population. Examples include the joint stock company, the US Electoral College, the IMF executive and the EU council of ministers. Power indices are a tool for address...

The weighted voting system used by the International Monetary Fund creates problems of democratic legitimacy since each member's influence or voting power is not in general equal to its voting weight. Using voting power analysis to analyse both the Board of Governors and the Executive Board, we show that it tends to enhance the power of the United...

Discrete choice experiments (DCE) and conjoint analysis (CA) are increasingly used to address health policy issues. This is because the DCE and CA approaches have theoretical foundations in the characteristics theory of demand, which assumes goods, services, or healthcare provision, can be valued in terms of their characteristics (or attributes). A...

Background Policies for allocating deceased donor kidneys have recently shifted from allocation based on Human Leucocyte Antigen (HLA) tissue matching in the UK and USA. Newer allocation algorithms incorporate waiting time as a primary factor, and in the UK, young adults are also favoured. However, there is little contemporary UK research on the vi...

Deriving Marginal Rate of Substitution (MRS) for attributes with respect to waiting time. Description: This file provides information on how marginal rates of substitution (point 7 of the ‘Methods’ section) were calculated using data obtained from econometric models 1 and 2 (outlined in Additional file 3).

Further details on the pilot exercise. Description: This file provides a more comprehensive description of the pilot exercise undertaken.

Copies of DCE questionnaires. Description: This file contains the questionnaires used in the DCE study. Copies of the following are provided: ●Questionnaire Version 4a: Patient version. ●Questionnaire Version 5b: Carer version. ●Questionnaire Version 6a: Healthcare professional version. ●Questionnaire Version 7b: Donor / relative of deceased donor...

Technical details about the econometric models (Model 1 and Model 2) used to establish stakeholder preferences ‘Econometric / statistical analysis.’ Description: This file provides a more detailed description of the econometric models used to underpin point 6 of the ‘Methods’ section.

Much current research in functional magnetic resonance imaging (fMRI) employs multivariate machine learning approaches (e.g., support vector machines) to detect distributed spatial patterns from the temporal fluctuations of the neural signal. The aim of many studies is not classification, however, but investigation of multivariate spatial patterns,...

Much current research in functional MRI employs multivariate machine learning approaches (e.g., support vector machines) to detect fine-scale spatial patterns from the temporal fluctuations of the neural signal. The aim of many studies is not classification, however, but investigation of multivariate spatial patterns, which pattern classifiers dete...

There is no consensus on the properties of voting power indices when there are a large number of voters in a weighted voting body. On the one hand, in some real-world cases that have been studied the power indices have been found to be nearly proportional to the weights (eg the EUCM, US Electoral College). This is true for both the PenroseBanzhaf a...

Revisions to UK transplant allocation policy in 2006 marked a policy shift towards ascribing higher priority to people who had been waiting for a long time for transplants, and to young adults, at the expense of emphasising tissue match between donor and recipient. This benefited members of ethnic minorities because of a shortage of donors from som...

An increasing trend in functional MRI experiments involves discriminating between experimental conditions on the basis of fine-grained spatial patterns extending across many voxels. Typically, these approaches have used randomized resampling to derive inferences. Here, we introduce an analytical method for drawing inferences from multivoxel pattern...

This paper reports the problems encountered in applying Markov Chain analysis to the Permanent sample of milk producers in England and Wales, and presents predictions obtained for producer numbers and milk output, by regions, for the years 1970/71 and 1975/76. As a consequence of the “pool of entrants” problem, dificulties arise both in estimating...

Weighted voting games are mathematical models, used to analyse situations where voters with variable voting weight vote in favour of or against a decision. They have been applied in various political and economic organizations. Similar combinatorial models are also encountered in neuroscience, threshold logic, reliability theory and distributed sys...

Weighted voting games are ubiquitous mathematical models which are used in economics, political science, neuroscience, threshold logic, reliability theory and distributed systems. They model situations where agents with variable voting weight vote in favour of or against a decision. A coalition of agents is winning if and only if the sum of weights...

The Double Majority rule in the Treaty is claimed to be simpler, more transparent and more democratic than the existing rule. We examine these questions against the democratic ideal that the votes of all citizens in whatever member country should be of equal value using voting power analysis considering possible future enlargements involving candid...

We propose an empirically informed measure of the voting power that relaxes the assumptions of equally probable and independent votes. The behavioral power index measures the voter’s ability to swing a decision based on the probability distributions of the others’ behavior. We apply it to the Supreme Court of the United States using roll-call data...

This paper provides an empirical analysis using power indices derived by regarding the Conference and Electoral College as weighted majority games. It is shown that both main power indices, the Shapley-Shubik and the Banzhaf, may be computed with reasonable accuracy by an approximation method based on probabilistic-voting assumption. The results sh...

We investigate the method of power indices to study voting power of members of a legislature that has voting blocs. Our analysis is theoretical, intended to contribute to a theory of positive political science in which social actors are motivated by the pursuit of power as measured by objective power indices. Our starting points are the papers by R...

As predicted by Duverger’s Law, the UK has two-party competition in each electoral district. However, there can be different patterns of two-party competition in different districts (currently there are five), so that there have usually been more than two effective parties in the Commons. Since 1874 it has always contained parties fighting seats in...

We consider some of the implications of a proposed reform of the voting system of the IMF in which EU countries cease to be separately represented and are replaced by a single combined representative of the European bloc. The voting weight of the EU bloc is reduced accordingly. We analyse two cases: the Eurozone of 12 countries and the European Uni...

As predicted by Duverger's Law, the UK has had two-party competition for long periods in most electoral districts. However, there are different patterns of two-party competition in different districts and more than two effective parties in the Commons. Since 1874, parliament has always contained parties wishing to modify the Union and contesting se...

We consider some of the implications of a proposed reform of the voting system of the IMF in which EU countries cease to be separately represented and are replaced by a single combined representative of the European bloc. The voting weight of the EU bloc is reduced accordingly. We analyse two cases: the Eurozone of 12 countries and the European Uni...

We discuss the nature of bloc voting and show that there is a fundamental distinction between voting weight and voting power. We analyse voting power, assuming that the G-7 countries form a bloc and find that it would disenfranchise all other countries while greatly enhancing the power of the United States, already more powerful than supposed. We c...

The main aim of this paper is to study the power of legislators in the Lower House of the Czech Parliament in 1996–2004 with respect to power distribution and its uncertainty. A discrepancy between a-priori computed power indices and outcome of voting leads to necessity to reveal the possible source of uncertainty. This paper studies uncertainty in...

Voting Power Indices enable the analysis of the distribution of power in a legislature or voting body in which different members have different numbers of votes. Although this approach to the measurement of power, based on co-operative game theory, has been known for a long time its empirical application has been to some extent limited, in part by...

The definition and implementation of control is at the heart of the corporate governance debate. The paper approaches the issue by using power indices derived from the theory of cooperative games. An application to Spanish listed firms shows that incentives for large shareholders to form controlling blocs are high. In the Spanish system of corporat...

This paper argues that the voting power approach is much more general than is portrayed by Albert (“The Voting Power Approach: Measurement without Theory”, European Union Politics, 4:3, 2003) and is therefore capable of generating important insights about voting systems, such as qualified majority voting in the EU Council. The voting power approach...

The paper reports on a study that tests the anecdotal hypothesis that parents are willing to pay a premium to secure places for their children in popular and oversubscribed comprehensive schools. Since many local education authorities use admissions policies that are based on catchment areas and places in popular schools are very difficult to obtai...

This paper considers the incentives faced by investors (financial institutions) to become actively involved in the direction of their under-performing portfolio companies as proposed by recent policy reports on corporate governance. It proposes a metric by which to measure the returns to activism in terms of the size of holding, measures of risk an...

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,...

This paper considers the incentives faced by investors (financial institutions) to become actively involved in the direction of their under-performing portfolio companies as proposed by recent policy reports on corporate governance. It proposes a metric by which to measure the returns to activism in terms of the size of holding, measures of risk an...

This paper describes the governance system of Spanish listed firms in the early 1990's. Although the institutional setting of the Spanish Stock Exchanges differs little from other European national markets, we found important differences in several aspects of corporate governance. In particular, some of the standard mechanisms of control (e.g. boar...

Lecture Notes prepared for Summer School, “EU Decision Making : Assessment and Design of Procedures”, San Sebastian, Spain, July 8-11, 2002.

In his well known 1971 paper the mathematical sociologist James S. Coleman, proposed three measures of voting power : (1) "the power of a collectivity to act", (2) "the power to prevent action" and (3) "the power to initiate action". (1) is a measure of the overall decisiveness of a voting body taking into account its size, decision rule and the we...

A priori voting power analysis can be useful in helping to design a weighted voting system that has certain intended properties. Power indices can help determine how many weighted votes each member should be allocated and what the decision rule should be. These choices can be made in the light of a requirement that there be a given distribution of...

Power indices are general measures of the relative a priori voting power of individual members of a voting body. They are useful for both positive and normative analysis of voting bodies particularly those using weighted voting. This paper applies new algorithms for computing the rival Shapley-Shubik and Banzhaf indices for large voting bodies to s...

The pattern of ownership and control of British industry is unusual compared with most other countries in that ownership is relatively dispersed. Typically the largest shareholder in any large listed company is likely to own a voting minority of the shares. Majority ownership by a single shareholder is unusual. It is not uncommon for the largest sh...

This paper reports on a study that tests the anecdotal hypothesis that parents are willing to pay a premium to secure places for their children in popular and oversubscribed comprehensive schools. Since many local education authorities use admissions policies based on catchment areas and places in popular schools are very hard to obtain from outsid...

In general in an organisation whose system of governance involves weighted voting, a member's weight in terms of the number of votes and the formal power it represents differ. Power indices provide a means of analysing this difference. The paper uses new algorithms for computing power indices for large games. Three analyses are carried out: (1) the...

This paper examines the system of Qualified Majority Voting, used by the Council of the European Union, from the perspective of enlargement of the Union. It uses an approach based on power indices due to Penrose, Banzhaf and Coleman to make two analyses: (1) the question of the voting power of member countries from the point of view of fairness, an...

This paper reports on a study that tests the anecdotal hypothesis that the prices of houses near popular comprehensive schools carry a premium. Since local education authorities use admissions policies based on catchment areas and places in popular schools are very hard to obtain from outside these areas - but easy from within them - parents have a...

In general in an organisation whose system of governance involves weighted voting, a member's weight in terms of the number of votes and the formal power it represents differ. Power indices provide a means of analysing this difference. The paper uses new algorithms for computing power indices for large games. Three analyses are carried out: (1) the...

This paper examines the system of Qualified Majority Voting, used by the Council of Ministers of the European Union, from the perspective of enlargement of the Union. It uses an approach based on power indices due to Penrose, Banzhaf and Coleman to make two analyses: (1) the question of the voting power of member countries from the point of view of...

The pattern of ownership and control of British industry is unusual compared with most other countries in that ownership is relatively dispersed. Majority ownership by a single shareholder is unusual. It is not uncommon for the largest shareholding to be under 20 percent and in many cases much less than that. A similar pattern occurs in the USA. Th...

This paper examines the system of Qualified Majority Voting, used by the Council of Ministers of the European Union, from the perspective of enlargement of the Union. It uses an approach based on power indices due to Penrose, Banzhaf and Coleman to make two analyses: (1) the question of the voting power of member countries from the point of view of...

An exercise in the empirical use of voting power indices from cooperative game theory applied to ownership data for large companies, this paper contributes in two areas: (1) the analysis of company control based on shareholder voting power, and (2) the empirical use of power indices and understanding of the comparative properties of different indic...

The pattern of ownership and control of British industry is unusual compared with most other countries in that ownership is relatively dispersed. Typically the largest shareholder in any large listed company is likely to own a voting minority of the shares. Majority ownership by a single shareholder is unusual. It is not uncommon for the largest sh...

Voting Power Indices enable the analysis of the distribution of power in a legislature or voting body in which different members have different numbers of votes. Although this approach to the measurement of power, based on co-operative game theory, has been known for a long time its empirical application has been to some extent limited, in part by...

In general in an organization whose system of governance involves weighted voting, a member's weight in terms of the number of votes and the formal power it represents differ. Power indices provide a means of analyzing this difference. The paper uses new algorithms for computing power indices for large games.

Voting Power Indices enable the analysis of the distribution of power in a legislature or voting body which uses weighted voting. Although the approach, based on co-operative game theory, has been known for a long time it has not been very widely applied, in part because of the difficulty of computing the indices when there are many players. This p...

In general in organisations whose system of governance involves weighted majority voting, power and voting weight differ. Power indices are a value concept for majority voting games which provide a means of analysing this difference. This paper provides new algorithms for computing the two classical power indices (the Banzhaf index and the Shapley-...

In general in organisations whose system of governance involves weighted majority voting, power and voting weight differ. Power indices are a value concept for majority voting games which provide a means of analysing this difference. This paper provides new algorithms for computing the two classical power indices (the Banzhaf index and the Shapley-...

This paper examines the relationship between top director pay, company performance and corporate governance in a sample of 294 U.K. companies between 1983 and 1986. The reported econometric results reveal that although a statistically significant relationship can be established between the growth in highest paid director salary and shareholder weal...

Ownership structure among 470 U.K. listed companies is described by concentration indices and by "control type," the latter defined using both a fixed percentage shareholding and the "degree of control." The authors also test for possible controlling coalitions among groups of shareholders. Control-type effects on performance are tested using reduc...

I study a budget-constrained, private-valuation, sealed-bid sequential auction with two incompletely-informed, risk-neutral bidders in which the valuations and income may be non-monotonic functions of a bidder's type. Multiple equilibrium symmetric bidding functions may exist that differ in allocation, efficiency and revenue. The sequence of sale a...

This paper reports an analysis of the relationships between shareholding and voting power distributions in a sample of British companies. It applies two standard approaches to the measurement of power in simple games: the Shapley-Shubik and the Banzhaf power indices. The results indicate that power is more concentrated than ownership in every case....

A model of the shareholder constraint is described in terms of the relationship between shareholding concentration and corporate control. A unified perspective (including takeovers as a special case) is developed whereby leading coalitions are costly to form and possess power in a shareholder voting game. Control is defined in terms of power indice...

This paper employs a simple-game-theoretic perspective to analyse the relationship between shareholding concentration and the voting power of leading coalitions among the top 200 non-financial corporations. The power index used to define controlling coalitions is the degree of control of Cubbin and Leech. The results show that, on the basis of obse...

The empirical findings of the classic study of the separation of ownership and control by A. A. Berle and G. C. Means (still authorita tive after more than fifty years) are reappraised. A probabilistic vo ting model is used to define rigorously minority ownership control an d a rule for determining control type. For the sixteen companies whic h Ber...

This paper adopts a new approach to the empirical testing of the Marris managerial theory of the firm and applies it to a cross-section sample of British companies in the early 1970s. It introduces three important innovations in the direct testing of the model: (i) a new exposition of the Marris theory if presented leading to a specification of the...

The relationship between shareholding concentration and shareholder voting power and the question of corporate control has long been recognised as being of central importance in the economies of the firm and has given rise to a large literature. Despite this, however, and the fact that quite sharp differences in perspective exist in this literature...

Capital market constraints on the firm are traditionally described as working through two mutually reinforcing mechanisms. Firct, a direct limitation on management discretion operates through accountability to shareholders. Larger shareholders are assumed continuously to monitor company performance particuarly in its effect on profitability and equ...

Berle and Means' classic study of the separation of ownership and control remains authoritative and influential despite having been criticised on various grounds by a number of authors. This paper argues that, firstly, the Berle and Means approach to determining company control implicitly assumes a static framework inappropriate to analysing early...

A large number of empirical studies have examined the question of the divorce between ownership and control as to either its extent (following Berle and Means (1932) or its implications for behaviour (following Marris (1964)). These studies have used different samples, different variables and have employed very different criteria to decide on the l...

This paper deals with the question of appropriately specifying the error structure in equations nonlinear in the parameters. An approach is presented which nests various disparate hypotheses (including those of additive normal and multiplicative lognormal error distributions) and suggests an approximate testing procedure. An example is given in whi...

This note shows that in the Sodrow-Miesowski-Wilson model, the Nash equilibrium in capital taxes depends on whether these taxes are unit (as assumed in the literature) or ad valorem (as in reality). In a symmetric version of the model with cobb-Douglas technology, public good provision is higher, and residents in both countries are better off, when...

We discuss the reform of the voting rules at the heart of the governance of the IMF and World Bank (the BWIs) in terms of three principles that we suggest ought to be fundamental: simplicity, transparency and democratic legitimacy. By simplicity we mean that the rules should make sense in terms of the purposes of the BWI and be easy to understand....