Survey and experimental methods to group decisions : equality of opportunity and weighted majority voting.

Summary This thesis is a compilation of essays that apply experimental and survey methods to two topics dealing with group decision making. Group decision-making is a type of participatory process in which several individuals act collectively, analyze problems or situations, examine and evaluate alternative courses of action, and choose from the various alternatives one or more solutions (Van den Ven & Delbeq, 1974). One of the most important characteristics of group decision making is that individuals have individual responsibility (Katzenbach & Smith, 1993). Therefore, this dissertation is concerned with both actual group-level decisions, but also with individual opinions.The first topic is in the area of welfare and social choice and focuses on equal opportunity (referred to as EOP thereafter). We first test the intuitive foundations of EOP by means of a survey, during which individuals are "unbiased spectators" without any personal gain. This survey allows us to illustrate the notion of impartial justice in the absence of interest. We then test the foundations in a non-cooperative experiment, where decisions made have consequences for individuals' gains. The experiment used in this topic focuses on the revealed justice preferences of decision makers. The second topic focuses on weighted majority voting systems (referred to as WMV hereafter). We first conduct a survey of different groups of students to find that individuals ignore the nonmonotonic relationship between the number of votes and the associated voting power. We then conduct several laboratory experiments to test whether this nonmonotonic relationship can be learned in a repeated game. Thus, the first part of this thesis includes two chapters about EOP, while the second includes two chapters about WMV. Chapter 1 is a general introduction, Chapter 6 presents the conclusions.Chapter 2 presents the EOP survey, which is a preference survey using multiple visuals to present hypothetical scenarios. This allows us to reveal individuals' preferences on the principles of EOP. To the best of our knowledge, our survey is the first attempt to fully explore the concept of EOP from the perspective of an "unbiased viewer." We systematically analyzed five factors that fall under the umbrella of EOP in two vignettes and several scenarios. Between the two vignettes: sales and alcohol, we found a high level of agreement on the circumstances. Not all individuals should suffer circumstance-related consequences in all situations for at least two reasons: first, this would clearly be morally arbitrary and second, because the resulting equalization must be adjusted. The thin consensus on effort and raw luck is also presented in our results. Since raw chance is defined in terms of the risk decay associated with the chance of non-option, it may lead to undesirable outcomes with respect to the EOP. Conversely, effort is defined as a reflection of the behavior of individuals. They control this effort, which influences their status. Thus, the effects of different levels of effort may not be neutralized.