Algorithmic and complexity aspects of simple coalitional games

Simple coalitional games are a fundamental class of cooperative games and voting games which are used to model coalition formation, resource allocation and decision making in computer science, artificial intelligence and multiagent systems. Although simple coalitional games are well studied in the domain of game theory and social choice, their algorithmic and computational complexity aspects have received less attention till recently. The computational aspects of simple coalitional games are of increased importance as these games are used by computer scientists to model distributed settings. This thesis fits in the wider setting of the interplay between economics and computer science which has led to the development of algorithmic game theory and computational social choice. A unified view of the computational aspects of simple coalitional games is presented here for the first time. Certain complexity results also apply to other coalitional games such as skill games and matching games. The following issues are given special consideration: influence of players, limit and complexity of manipulations in the coalitional games and complexity of resource allocation on networks. The complexity of comparison of influence between players in simple games is characterized. The simple games considered are represented by winning coalitions, minimal winning coalitions, weighted voting games or multiple weighted voting games. A comprehensive classification of weighted voting games which can be solved in polynomial time is presented. An efficient algorithm which uses generating functions and interpolation to compute an integer weight vector for target power indices is proposed. Voting theory, especially the Penrose Square Root Law, is used to investigate the fairness of a real life voting model. Computational complexity of manipulation in social choice protocols can determine whether manipulation is computationally feasible or not. The computational complexity and bounds of manipulation are considered from various angles including control, false-name manipulation and bribery. Moreover, the computational complexity of computing various cooperative game solutions of simple games in dierent representations is studied. Certain structural results regarding least core payos extend to the general monotone cooperative game. The thesis also studies a coalitional game called the spanning connectivity game. It is proved that whereas computing the Banzhaf values and Shapley-Shubik indices of such games is #P-complete, there is a polynomial time combinatorial algorithm to compute the nucleolus. The results have interesting significance for optimal strategies for the wiretapping game which is a noncooperative game defined on a network

Measuring the organizational effectiveness of public-private partnerships: A Case study of the Department of Energy’s Clean Cities public-private partnership program

This thesis measures the organizational effectiveness of public-private partnerships (PPPs) by using the DOE\u27s Clean Cities PPP program as a case study. A survey was sent to 109 Clean Cities coordinators with questions pertaining to coalition characteristics and strategies. The survey results formed the basis for the analysis of the effectiveness of the coalitions. Coalitions can have an independent or subsidiary organizational structure. Furthermore, the broad/overarching organizational structure of Clean Cities coalitions serves as an important characteristic that determines a coalition\u27s organizational operations. In measuring the Clean Cities program in terms of organizational effectiveness, the structure of coalitions (e.g., independent and subsidiary) appeared to be a central variable to use in differentiating the coalitions. By examining statistically if independent and subsidiary coalitions were the same or different across several categories (e.g., coalition characteristics and collaboration success with various stakeholders), this research found that the broad/overarching organizational structure made no difference in the ability of members to deliver results successfully. However, some differences were found in examining if subsidiary and independent coalitions were the same or different across other categories that could not be examined statistically, such as other coalition characteristics and the strategies members use in carrying out their organization\u27s mission statement. From this analysis, it can be concluded that even though a coalition\u27s broad/overarching structure makes little to no difference in determining organizational success, how an organization\u27s internal structure is developed and/or managed was found to be important to members in delivering results successfully. A coalition\u27s internal organizational structure refers to the strategies members use to get work done and fulfill their missions. A coalition\u27s internal structure and other key characteristics of success highlighted by survey respondents were consistent with findings in the literature describing the success factors for public-private partnerships

Policy learning over a decade or more and the role of interests therein

When individual actors are involved in a policy process, do they assess and revise their policy preferences according to their interests or are they open to other forms of arguments over time? This study examines the effect of policy actors’ interests on policy learning. It is based on a survey conducted in 2012 among 376 Belgian actors (from 38 organizations) involved in the European liberalization policy process of two network industries: the rail and electricity sectors. Borrowing from organizational research and behavioral economics, several hypotheses are drawn from a model of the individual shared by various policy approaches, such as the advocacy coalition framework. A ‘‘simple gain scores’’ approach to the measurement of policy learning is introduced. Regression analyses show that policy actors align their policy preferences with the impacts of policies on their own material well-being (personal interests) and the material prosperity of their organization (organizational interests). This tendency is independent of the importance that policy actors give to their interests in their everyday lives. This suggests that policy actors experience a sort of ‘‘interest shift’’ when they assess their policy preferences over time. This shift, however, exerts a limited influence on policy learning. The theoretical and practical implications are discussed

Balancing Apples and Oranges: Methodologies for Facility Siting Decisions

Evaluating alternative sites for major constructed facilities requires comparing impacts of different levels and different types to establish desirable yet feasible balances. Currently employed and proposed, methodologies for evaluating the desirability of sets of impacts generated by large facilities are compared, and the theoretical assumptions implicit in each are discussed. In aggregate, the three sets of methodologies considered are Cost-Benefit Analysis and its various modifications, matrix or tableau methods of several sorts, and, preference theory (of which utility is a special case). Primary attention is given to the structure of objective functions defined over impacts

A MATHEMATICAL ANALYSIS OF CONFLICTS IN VOTING SYSTEMS

Game Theory applied to voting gives rise to the study of many different topics. In this thesis we present some results in order to evaluate the power share inside a Parliament, to analyze the criteria for the assessment of the voters\u2019 preferences and to provide more efficient ways to compute the existing instruments. The first part of the thesis deals with the issue of power in a voting system. In order to better analyze it, we investigate the way of combining a communication structure with the already existing indices of power. Moreover, we present the possibility of assuming some coalitions as less probable, but not infeasible, as the political scenario is complex enough to admit the possibility of very unlikely coalitions to form. Then, we add another important aspect to the problem; the alliances inside a decisional situation are not stable, but may evolve with time, mainly due to the fact that each agent aims at getting a higher power. We refer to an already existing instrument which, theoretically, may perfectly describe this situation. Unfortunately, the current computational complexity does not permit to adopt it in many real cases. Another important topic is the evaluation of the power to block instead of the power to win. We provide an index which evaluates the veto power and which can be extended in order to catch other characteristics of the game; for example, the probability that a party takes a particular decision, or that not every member of a party is present at the vote. The second part of this thesis considers a previous step of the formation of a democracy: the evaluation of how much the resulting Parliament reflects the preferences expressed by the electors. We think that the goodness of a Parliament mainly depends on the power share between the parties and not only on the number of seats. Finally, the last part shows a new exact method to improve the efficiency of the evaluation of one of the existing indices of power, the Public Good index