Measuring voting power in convex policy spaces

Classical power index analysis considers the individual's ability to influence the aggregated group decision by changing its own vote, where all decisions and votes are assumed to be binary. In many practical applications we have more options than either "yes" or "no". Here we generalize three important power indices to continuous convex policy spaces. This allows the analysis of a collection of economic problems like e.g. tax rates or spending that otherwise would not be covered in binary models.Comment: 31 pages, 9 table

The Inter-Institutional Distribution of Power in EU Codecision

This paper analyzes the a priori influence of the European Parliament (EP) and the Council of Ministers (CM) on legislation of the European Union adopted under its codecision procedure. In contrast to studies which use conventional power indices, both institutions are assumed to act strategically. Predicted bargaining outcomes of the crucial Conciliation stage of codecision are shown to be strongly biased towards the legislative status quo. Making symmetric preference assumptions for members of CM and EP, CM is on average much more conservative because of its internal qualified majority rule. This makes CM by an order of magnitude more influential than EP, in contrast to a seeming formal parity between the two ‘co-legislators’.power measurement, European Union codecision procedure, bargaining, spatial voting, decision procedures

Mostly sunny : a forecast of tomorrow's power index research

Power index research has been a very active field in the last decades. Will this continue or are all the important questions solved? We argue that there are still many opportunities to conduct useful research with and on power indices. Positive and normative questions keep calling for theoretical and empirical attention. Technical and technological improvements are likely to boost applicability.Comment: 12 page

Fair Representation and a Linear Shapley Rule

When delegations to an assembly or council represent differently sized constituencies, they are often allocated voting weights which increase in population numbers (EU Council, US Electoral College, etc.). The Penrose square root rule (PSRR) is the main benchmark for fair representation of all bottom-tier voters in the top-tier decision making body, but rests on the restrictive assumption of independent binary decisions. We consider intervals of alternatives with single-peaked preferences instead, and presume positive correlation of local voters. This calls for a replacement of the PSRR by a linear Shapley rule: representation is fair if the Shapley value of the delegates is proportional to their constituency sizes.Comment: 21 pages, 2 figure

Why Is Change so Slow? Assessing Prospects for United Nations Security Council Reform

The article explores how changed patterns of UN membership affected the prospects for UN Security Council institutional reform. First, we outline a theoretical framework based on path dependency, veto player analysis and social choice theory. Second, we offer calculations of decision probability and show that a higher voting threshold lowers chances of winning coalitions in a non-linear fashion. Third, we explore the specific decision-making procedures for UNSC reform and which actors can block reform. We conclude that not only diverging preferences, but that hurdles established early on combined with membership growth have ‘locked in’ the current institutional arrangement.Security and Global Affair

Extensions of the shapley value in weighted voting systems

The present work reviews the concept of values in the theory of games with particular reference to political games. A model based on the Shapley value concept is developed and applied to simulated and practical voting situations. In particular it is shown how numerical expressions can be obtained for the values of each group or party given their sizes and with knowledge of their previous voting patterns. Data based on the Nigerian political set up as well as other political systems, including the U.N., E.E.C. etc. was used for calculating the values of the different participants

Disentangle the Florentine Families Network by the Pre-Kernel

For different model settings we conduct power analyses on the Florentine families network of the 15th century while referring to the most popular power indices like the Shapley-Shubik or Banzhaf value as well as to the pre-nucleolus and pre-kernel. In order to assess their capacity to identify the main protagonists that correspond with the chronicles, we inspect of how the power distributions are spread around the mean. Distributions that are clustered to close around the mean cannot identify outstanding positions. In this respect, they failed to provide a scenario that corresponds with the annals. As it turns out, the pre-kernel solution – as a solution concept designed for studying bargaining situations – retrieves the most accurate image for the examined network structures. Last but not least, we discovered two new non-homogeneous weighted majority games with a disconnected pre-kernel