Population monotonic path schemes for simple games

A path scheme for a game is composed of a path, i.e., a sequence of coalitions that is formed during the coalition formation process and a scheme, i.e., a payoff vector for each coalition in the path. A path scheme is called population monotonic if a player’s payoff does not decrease as the path coalition grows. In this study, we focus on Shapley path schemes of simple games in which for every path coalition the Shapley value of the associated subgame provides the allocation at hand. Obviously, each Shapley path scheme of a game is population monotonic if and only if the Shapley allocation scheme of the game is population monotonic in the sense of Sprumont (Games Econ Behav 2:378–394, 1990). We prove that a simple game allows for population monotonic Shapley path schemes if and only if the game is balanced. Moreover, the Shapley path scheme of a specific path is population monotonic if and only if the first winning coalition that is formed along the path contains every minimal winning coalition. We also show that each Shapley path scheme of a simple game is population monotonic if and only if the set of veto players of the game is a winning coalition. Extensions of these results to other efficient probabilistic values are discussed.     

Separator-based data reduction for signed graph balancing

Polynomial-time data reduction is a classical approach to hard graph problems. Typically, particular small subgraphs are replaced by smaller gadgets. We generalize this approach to handle any small subgraph that has a small separator connecting it to the rest of the graph. The problem we study is the NP-hard Balanced Subgraph problem, which asks for a 2-coloring of a graph that minimizes the inconsistencies with given edge labels. It has applications in social networks, systems biology, and integrated circuit design. The data reduction scheme unifies and generalizes a number of previously known data reductions, and can be applied to a large number of graph problems where a coloring or a subset of the vertices is sought. To solve the instances that remain after reduction, we use a fixed-parameter algorithm based on iterative compression with a very effective heuristic speedup. Our implementation can solve biological real-world instances exactly for which previously only approximations were known. In addition, we present experimental results for financial networks and random networks.     

A tighter formulation of the <Emphasis Type=Italic>p</Emphasis>-median problem

Given a set of clients and a set of potential sites for facilities, the p-median problem consists of opening a set of p sites and assigning each client to the closest open facility to it. It can be viewed as a variation of the uncapacitated facility location problem. We propose a new formulation of this problem by a mixed integer linear problem. We show that this formulation, while it has the same value by LP-relaxation, can be much more efficient than two previous formulations. The computational experiment performed on two sets of benchmark instances has showed that the efficiency of the standard branch-and-cut algorithm has been significantly improved. Finally, we explore the structure of the new formulation in order to derive reduction rules and to accelerate the LP-relaxation resolution.     

Federalism and the Implementation of Environmental Policy: Changing Trends in Canada and the United States

In a federal system of government, powers are shared by the national and sub-national units in accordance with the provisions of the Constitution. However, the process of policy implementation may differ on the basis of allocation of power and the nature of the system. Canada and the United States of America adopted federal systems of government, and faced similar pressures for implementing policies on environmental issues. Yet, the degree of success and outcome appear to be different due to variations in the strength of the respective federalist systems. An analysis of the various aspects of the federal system in the two countries reveals noticeable differences in institutional configurations, relationship between national and sub-national units, and variances in intra-institutional relations. All these have contributed to a divergence in the past, but there is an emerging trend of convergence as both the Canadian and American governments are gradually moving away from their existing patterns of policy implementation toward a new approach involving private-sector initiatives and self-enforcement with strong inclinations toward voluntarization, corporatization and marketization.     

Birds of a Feather? The Effect of Organizational Value Congruence on the Relationship Between Ministries and Quangos

In this paper we investigate differences between the organizational values of ministries and semi-autonomous executive agencies (quangos) that operate at arms’ length. Quangos are expected to operate more business-like, hence they can be expected to value profitability and other NPM-related values higher than ministries. Value incongruence between quangos and ministries is hypothesized to decrease their level of trust. These hypotheses are tested, using combined data from two Dutch surveys (n = 324). The results confirm the expectations, although different types of quangos have different degrees of value (in)congruence, which may lead to variations in the quality of the relationship with their parent ministry.     

National Defense,Environmental Regulation,and Overhead Democracy: A View from the “Greening” of the U.S. Military

This study examines the patterns of politics accompanying efforts to hold the United States military accountable to U.S. environmental and natural resources (ENR) laws in the post-Cold War era. This analysis (1) uses three cases to describe what happened, and why, (2) to test several propositions related to military accountability to ENR laws in the post-Cold War era; (3) to offer a typology of tactics used that may help inform future research on intragovernmental regulation more generally; and (4) argues that public agencies have a responsibility to comply with the regulatory processes that hold them accountable to U.S. ENR laws.     

Regulation by disclosure: the case of internal control

In this paper we explore the use of disclosure as a regulatory tool, using as an illustration the current UK requirements regarding the disclosure of information about internal control. After discussing the broad concept of regulation by disclosure, we trace the evolution of concepts of internal control and its reporting, describing the background to the Turnbull guidance for directors on internal control reporting, the basis of current UK requirements. We then examine recent examples of internal control disclosures, identifying the range of ways in which they address the disclosure requirements and considering the possible impact of the disclosure requirements on corporate behaviour and on the audiences for disclosure. We conclude with some reflections on the disclosure life cycle. The paper contributes to the literature on disclosure by specifically considering the role of disclosure as a regulatory tool and by examining the nature of specific disclosures in an area of continuing interest, that of internal control.     

Country-specific institutional effects on ownership: concentration and performance of continental European firms

This paper examines the effect of country-specific institutional constructs on the relationship between ownership concentration and performance for firms in the eight Continental European countries of Austria, Belgium, Germany, Spain, France, Italy, the Netherlands and Portugal. Using data from publicly-traded firms owned by other companies (i.e., blocks), measures of the quality of investor and creditor protection and the effectiveness of legal institutions are applied. Employing a hierarchical moderated multiple regression analysis, differential validity is established for the relationship between ownership concentration and performance as measured by return on shareholders’ funds. This differential effect comes from creditor protection regimes and is consistent with a relational corporate governance model based on debt finance and concentrated ownership.