Unanimity Rule Research Articles

The k -Unanimity Rule for Self-Organized Decision-Making in Swarms of Robots.

In this paper, we propose a collective decision-making method for swarms of robots. The method enables a robot swarm to select, from a set of possible actions, the one that has the fastest mean execution time. By means of positive feedback the method achieves consensus on the fastest action. The novelty of our method is that it allows robots to collectively find consensus on the fastest action without measuring explicitly the execution times of all available actions. We study two analytical models of the decision-making method in order to understand the dynamics of the consensus formation process. Moreover, we verify the applicability of the method in a real swarm robotics scenario. To this end, we conduct three sets of experiments that show that a robotic swarm can collectively select the shortest of two paths. Finally, we use a Monte Carlo simulation model to study and predict the influence of different parameters on the method.

The unanimity rule and extremely asymmetric committees

This paper analyzes how to allocate experts into committees that use the unanimity rule to make decisions. We show that an optimal allocation of experts is extremely asymmetric. To reach the optimal allocation, therefore, one needs only to rank the experts in terms of their abilities and then allocate adjacent experts such that an expert’s ability tends to vary inversely with the size of his committee. In the special case of three-member committees, we show that the optimal allocation maximizes the sum of the products of the experts’ skills in each committee.

Single-dipped preferences with satiation: strong group strategy-proofness and unanimity

We study the problem of the location of a public facility that generates negative externalities. We consider that agents have single-dipped preferences with satiation: each agent considers a location as the worst, the “dip”, and the farther the location is from the dip, the better for the agent. In addition, an agent might be indifferent between all the locations sufficiently far from his dip, reaching his highest level of satisfaction. We characterize the family of strongly group strategy-proof and unanimous rules. Opposite to previous results without satiation, the locations selected are not necessarily at the extremes of the alternatives’ space.

Contractually Stable Alliances

We analyze how different rules for exiting an alliance affect the formation of strategic alliances. We adopt the concept of contractual stability to predict the alliances that are going to emerge in the long run. We find that any asymmetric alliance structure consisting of two alliances is contractually stable under the unanimity decision rule. In addition, the grand alliance which is the efficient structure is stable. If we allow for side payments to compensate former partners, then some less efficient structures that were stable without side payments are no longer stable. Moreover, we show that the stability of alliances under the unanimity rule to exit is robust to the type of firms, myopic or farsighted. Finally, there is no contractually stable alliance structure under the simple majority decision rule.

From Consumer Decision to Market Share – Unanimity of Majority?

We use a general cellular automata model to study the consumer decision-making process. Within this general model we use three different rules governing word-of-mouth communication (w-o-m), one majority rule and two unanimity rules, and ask the question if differences between these three w-o-m rules, introduced on the microscopic level, will manifest on the macroscopic level. We show that in the model with the majority rule the neighborhood plays a significant role in terms of the market shares whereas movement (interpreted as seeking for information in other sources) is almost negligible. Exactly the opposite phenomena are observed for models in which unanimity, instead of majority, is needed to convince agents. We also introduce a modification of the unanimity rule, based on the Latane theory of the social influence, and show that on the macroscopic level this modification is indistinguishable from the simple unanimity rule. We conclude the paper with a recommendation which rules are more appropriate to model particular marketing phenomena.

Direct Democracy: Chances and Challenges

This paper discusses several problems of direct popular decisions that are often overlooked in political and scientific debates. In the first part, we consider problems related to the functioning of direct democracy. As a political system, it only makes sense if there exists a continuous process and not if only occasional single questions are brought to a referendum. Then, the relation between direct democracy and the rule of unanimity is discussed, a subject of special relevance to the European Union, before we consider the role of quorums. In the second part, some areas are considered in which conflicts might arise. Results of initiatives might be incompatible with individual human rights or might endanger fiscal sustainability, and referenda might impede economic reforms. All these problems, however, do not justify a general rejection of direct popular rights. Thus, we conclude by listing several points that should be observed to safeguard the well- functioning of direct democracy.

The Unanimity Rule and Extremely Asymmetric Committees

The Unanimity Rule and Extremely Asymmetric Committees

The Unanimity Rule and Extremely Asymmetric Committees

This paper analyzes how to allocate experts into committees that use the unanimity rule to make decisions. We show that an optimal allocation of experts is extremely asymmetric. To reach the optimal allocation, therefore, one needs only to rank the experts in terms of their abilities and then allocate adjacent experts such that an expert's ability tends to vary inversely with the size of his committee. In the special case of three-member committees, we show that the optimal allocation maximizes the sum of the products of the experts' skills in each committee.

How global institutions rule the world

Introduction 1. World Government is Here PART I: WHO RULES 2. Network Goods are Served by Simple Bureaus 3. Unanimity Rule Failed to Make the World More Secure 4. A Great-Powers' Directorate Has Averted the Third World War 5. Weights and Coalitions for Finance and Development 6. Equal Vote Does Not Favor Global Trade 7. The World's Self-Appointed Steering Committee PART II: HOW THEY RULE 8. Domestic Politics Doesn't Make Policy 9. Global Representation Requires Rotation of Countries 10. Effective Decisions are Made by Means of Weighted Votes 11. Expert Rulers Replace Politicians and Diplomats 12. Policy Consensus is Built With More Ideas than Votes 13. Non-Electoral Accountability is Based On Performance and Values 14. Can Global Democracy Exist

Wicksell, Pareto and Public Choice

No individual in the history of public economics has been subject to more contentious discussion than Knut Wicksell – and perhaps no concept subjected to more diverse interpretation than Wicksell’s unanimity rule. The story begins in 1896 with the publication of Wicksell’s public finance treatise, Finanztheoretische Untersuchungen, and starts to take shape in 1906 with the publication of Pareto’s Manual of Political Economy. The crux of the matter hinges on the relationship between Wicksell’s unanimity rule and Pareto’s optimality. This article examines Knut Wicksell’s one-sided debate with Vilfredo Pareto on issues in welfare economics and considers the trajectory of their economic ideas that led to an eventual convergence in public choice.

Jury voting without objective probability

Unlike in the standard jury voting experiment, the voting environment in practice has no explicit signal structure. Voters then need to conceptualize the information structure in order to update their beliefs based on “pivotal reasoning”. This paper investigates whether voters can play a strategic voting under a “detail-free” environment. We obtain non-parametric predictions in terms of the differences in voting behaviors under majority and unanimity rule. Our experimental results suggest that voters can still play the strategic voting as in the existing experiments.

El Tribunal Constitucional chileno y la reforma de 2005: Un enroque entre jueces de carrera y académicos

After a constitutional amendment in 2005, the Chilean Constitutional Tribunal is becoming more active in exercising its powers against the executive branch. This effect is mainly due to a castling in the composition of the court between career judges and justices coming from the academia. Chilean judges have had a long-standing reputation of being deferential with the government and of following a rule of unanimity. That attitude, however, goes beyond partisan affiliation. As it is shown in this paper, the changes in the behavior of the court seems to be more related with a change in the underlying legal culture, than with differences in the partisan affiliation of the justices. Chilean Constitutional Tribunal – Unanimous Judicial Opinions – Dissenting Opinions

Member States Resistance to EU Foreign Policy Sanctions

European Union (EU) sanctions are agreed in the Common Foreign and Security Policy (CFSP), a framework where the unanimity rule prevails and where individual Member States have a formal veto. Thus, Member State compliance with sanctions can be expected to be optimal: If Member States have serious objections to the imposition of sanctions, they can veto their adoption in the Council. Yet, while implementation is comparatively satisfactory, Member States have availed of opportunities to undermine the application of EU sanctions regimes at various levels. On the basis of the theoretical framework provided by Saurugger and Terpan, the present article explores various ways in which Member States attempt to resist EU measures, categorizes them and explains Member States’ choice of resistance techniques.

Committees with leaks

We analyze the quality (informativeness and efficiency) of advice obtained from a committee of careerist experts where voting is secret but voting profiles are ‘leaked’ with an exogenously given probability. We show that fully informative voting is achievable only when the common prior is not too informative, the committee uses the unanimity rule and faces random leakage. It is then shown that informativeness and efficiency are mutually exclusive properties of committees with careerist experts.

Subgroup deliberation and voting

We consider three mechanisms for the aggregation of information in heterogeneous committees voting by Unanimity rule: Private Voting and voting preceded by either Plenary or Subgroup Deliberation. While the first deliberation protocol imposes public communication, the second restricts communication to homogeneous subgroups. We find that both protocols allow to Pareto improve on outcomes achieved under private voting. Furthermore, we find that when focusing on simple equilibria under Plenary Deliberation, Subgroup Deliberation Pareto improves on outcomes achieved under Plenary Deliberation.

Variational Bewley preferences

This paper characterizes variational Bewley preferences over Anscombe and Aumann acts, a class of binary relations that may fail completeness or transitivity vis à vis independence. The main result gives an axiomatization of preference relations ≿ represented as follows:f≿g⇔∫u(f)dp+η(p)≥∫u(g)dp for all p∈Δ, where u is an affine utility index over a convex set X of consequences, η:Δ→[0,∞] is an ambiguity index, and Δ is the set of priors over the state space S. This representation has a natural interpretation as a weighted unanimity rule, with the function η reflecting the weight given to a prior and higher values of η corresponding to priors given less weight. Bewley's incomplete preferences can be identified precisely with the addition of transitivity or independence, and a prior receives weight either 0 if plausible or ∞ when discarded. Also, by adding only completeness, we recover subjective expected utility, i.e., the lack of transitivity implies incompleteness. Finally, we find a strong connection of our model with the class of variational preferences.

Counting the many: the origins and limits of supermajority rule

Supermajority rules govern many features of our lives in common: from the selection of textbooks for our children's schools to residential covenants, from the policy choices of state and federal legislatures to constitutional amendments. It is usually assumed that these rules are not only normatively unproblematic but necessary to achieve the goals of institutional stability, consensus, and minority protections. In this book, Melissa Schwartzberg challenges the logic underlying the use of supermajority rule as an alternative to majority decision making. She traces the hidden history of supermajority decision making, which originally emerged as an alternative to unanimous rule, and highlights the tensions in the contemporary use of supermajority rules as an alternative to majority rule. Although supermajority rules ostensibly aim to reduce the purported risks associated with majority decision making, they do so at the cost of introducing new liabilities associated with the biased judgments they generate and secure.

Group size and decision rules in legislative bargaining

We experimentally investigate the effects of group size on behavior and outcomes in a multilateral bargaining game. Using a Baron–Ferejohn protocol, our main interest is in the extent of costly delay (number of bargaining rounds needed to reach agreement). We investigate the effects of group size on delay under both majority and unanimity rule. Under both decision rules, we find that proposals more often fail in larger groups, leading to increased delay. Consistent with prior research, we also find that unanimity rule leads to more delay than does majority rule, in both small and large groups. Contrary to one of our initial hypotheses, we find that the latter effect is not more pronounced in larger groups. The higher rate of failure in larger groups and under unanimity rule is driven by a combination of three factors: (1) a larger number of individuals must agree, (2) an important fraction of individuals reject offers below the equal share, and (3) proposers demand more (relative to the equal share) in large groups.

The value of formalism: re-examining external costs and decision costs with multiple groups

Several authors have examined the optimal k-majority rule using a variety of criteria. We formalize and extend the original argument laid out by Buchanan and Tullock (The calculus of consent: logical foundations of constitutional democracy, 1962) using a decision theoretic analysis from the perspective of an individual voter. Unlike previous formalizations, voters in our study are members of one or more groups. This allows us to examine cases wherein different voters have starkly different interests. Furthermore, voters in our study can err in their judgments of proposals allowing us to model potential irra- tionalities in the choice of an optimal k-majority rule. We consider both up or down votes on a single proposal as well as votes over a series of proposals. We find that the optimal k- majority rule depends on a number of parameters, most notably the number of rounds needed to create a proposal that will pass. Group membership has almost no affect. Fur- thermore, if two groups are at odds, then the external cost function can actually rise over some range of k; if voters err systematically in their judgment, more inclusive k-majority rules, such as unanimity rule, can fail to pass Pareto preferred proposals. Our results should help advance a classic work in Public Choice.

Mock jury trials in Taiwan—Paving the ground for introducing lay participation.

The first mock jury study in Taiwan, in which 279 community members watched a videotaped trial, investigated how jurors' estimates of the relative undesirability of wrongful conviction versus wrongful acquittal predicted individual decisions and how decision rules affected outcomes. The percentage of jurors who viewed wrongful conviction as more undesirable increased from 50.9% to 60.9% after deliberation and jurors' postdeliberation acquittal rate (71.7%) was higher than predeliberation acquittal rate (58.8%). Jurors' estimates of the undesirability of wrongful conviction were not correlated with their predeliberation votes but became positively correlated with their postdeliberation decisions. The unanimous rule facilitated jurors' change of vote, predominantly from conviction to acquittal, than the simple majority rule. Jurors reaching a verdict under the unanimous rule viewed deliberation and the verdict more positively. This study indicates that deliberation can ameliorate the problem of most Taiwanese citizens not viewing wrongful conviction as more undesirable than wrongful acquittal. It also suggests that Taiwan should adopt a unanimous rule for its proposed lay participation system.