A collective model for the formation of public opinion: An application to nuclear public acceptance

A collective model is proposed for the formation of public opinion and applied to the problem of public acceptance for nuclear energy in Japan. The selection of attitude for the people to a certain subject is assumed to be made depending on the sociopsychological pressure suffering from the surroundings, and on the quality and quantity of information on that subject released from the newsmedia. The reportorial stance of the newsmedia, on the other hand, is assumed to vary depending on, not only public opinion, but also the resultant of the mutual watch of the newsmedia to each other, concerning the state of information on the subject. Both an individual person and an individual medium are regarded as an interactive but structureless particle, and the interactions between the particles of the people and of media are described by introducing respective potentials of the type of molecular dynamics. Applying this model to the issue of electricity generation by nuclear energy, it was found to well reproduce the observed movement of public opinion in Japan. It also became clear that this sort of physical model is quite useful for understanding the status of socially collective phenomena in which nonlinearity and self-organization are strongly concerned.     

Efficiency and welfare implications of managed public sector hospital waiting lists

A queuing model for public health service waiting lists is developed, and the implications for patient welfare of different systems for managing the waiting list are analysed. If patients are admitted to hospital on a first-come-first-served basis, a welfare gain is achieved by moving from a system of implicit to one of explicit rationing of access to the waiting list. If individual waiting times and hospital admissions are dependent on clinical priority, a further welfare gain is achievable without the use of explicit rationing, by reallocating the total waiting time from the more towards the less seriously ill. On efficiency and welfare criteria, a maximum waiting time guarantee does not appear to be a desirable development.     

Group differences in broadness of values may drive dynamics of public opinion on moral issues

Here we propose the idea that the success of an argument in favor of an issue position should depend on whether the argument resonates with the audience’s values. Now consider two groups, one of which has a broader set of values than the other. We develop a mathematical model to investigate how this difference in broadness of values may drive a change on the population level towards positions in line with the more narrow set of values. The model is motivated by the empirical finding that conservative morality rests equally on moral foundations that are individualizing (harm and fairness) and binding (purity, authority, and ingroup), whereas liberal morality relies mainly on the individualizing moral foundations. The model then predicts that, under certain conditions, the whole population will tend to move towards positions on moral issues (e.g., same-sex marriage) that are supported by individualizing moral foundations.     

An experimental study of voting rules and polls in three-candidate elections

We report the results of elections conducted in a laboratory setting, modelled on a threecandidate example due to Borda. By paying subjects conditionally on election outcomes, we create electorates with (publicly) known preferences. We compare the results of experiments with and without non-binding pre-election polls under plurality rule, approval voting, and Borda rule. We also refer to a theory of voting “equilibria,” which makes sharp predictions concerning individual voter behavior and election outcomes. We find that Condorcet losers occasionally win regardless of the voting rule or presence of polls. Duverger's law (which asserts the predominance of two candidates) appears to hold under plurality rule, but close three-way races often arise under approval voting and Borda rule. Voters appear to poll and vote strategically. In elections, voters usually cast votes that are consistent with some strategic equilibrium. By the end of an election series, most votes are consistent with a single equilibrium, although that equilibrium varies by experimental group and voting rule.     

Consensus of opinion

In a decision analysis, it is often necessary to combine a group of individuals' beliefs into a consensus probability distribution. This paper addresses the question whether it is possible to base such consensus distributions only upon the information present within the group or must some arbitrary rule be used to resolve disagreement. Some earlier work on modifying beliefs in the light of another's opinion is developed to apply to groups of n people. Using this as a “benchmark of rationality”, standard methods of forming group consensus probability distributions are found somewhat arbitrary. Furthermore it is argued that the possibility of constructing better procedures is remote.     

The generation of a social welfare function under ordinal preferences

Against the background of recent impossibility theorems, the paper establishes a number of rules for the formation of social preferences to ensure the generation of a Bergson-Samuelson social welfare function of the desired ‘individualistic’ form. It demonstrates that such welfare functions can indeed exist under conditions of simply ordinality of individual preferences and a lack of interpersonal comparability, for the general n-person case with only weak restrictions upon individual preferences. A valuable tool of social welfare theory for the single-profile case is therefore restored under a wide set of conditions. By examining Kemp and Ng's justification for their A3 condition in this context, we are able also to highlight a number of key differences between the conditions satisfied by many political constitutions and the requirements for achieving the positive existence of a Bergson-Samuelson social welfare function. In particular the paper focusses here on the weighting systems on individual preferences that are consistent with generating an individualistic welfare function and examines the information content of individual ordinal preferences which must be utilized if the desired welfare function is to result.     

The Shapley value as the maximizer of expected Nash welfare

We provide an alternative interpretation of the Shapley value in TU games as the unique maximizer of expected Nash welfare.     

The private value of public pensions

As individual retirement savings accounts replace public pensions and defined benefit schemes, more retirees will decumulate using commercial income streams rather than public or corporate annuities. Here we use an approximation to the retirement income problem [Huang, H., Milevsky, M.A., Wang, J., 2004. Ruined moments in your life: How good are the approximations? Insurance: Math. Econom. 34, 421–447] to compute the cost of replicating a public real life annuity (the Australian Age Pension) using commercial decumulation products. We treat the public pension as a phased withdrawal plan, matching insurance and payment features, and back out the stochastic present value of the plan under an arbitrarily small ruin probability. To reproduce the pension payment with 99% certainty, a male retiree needs 3.6 times the current average retirement savings account balance, and a female retiree needs more than 10 times the average female account balance. At 95% certainty, required wealth falls by around 25%. We measure separately the impact of gender, investment strategy, retirement age and management fees on this valuation.     

Consensus formation of two-level opinion dynamics

Opinion dynamics have received significant attention in recent years. This paper proposes a bounded confidence opinion model for a group of agents with two different confidence levels. Each agent in the population is endowed with a confidence interval around her opinion with radius αd or (1-α)d, where α ∈ (0,1/2] represents the differentiation of confidence levels. We analytically derived the critical confidence bound d_c = 1/(4α) for the two-level opinion dynamics on ?. A single opinion cluster is formed with probability 1 above this critical value regardless of the ratio p of agents with high/low confidence. Extensive numerical simulations are performed to illustrate our theoretical results. Noticed is a clear impact of p on the collective behavior: more agents with high confidence lead to harder agreement. It is also experimentally revealed that the sharpness of the threshold d_c increases with α but does not depend on p.     

Metric rationalization of social welfare functions

Metric rationalization of social decision rules has been intensively investigated when the social outcome is a nonempty subset of alternatives. The present paper proposes a similar framework for social welfare functions (SWFs)—that is when each social outcome is a ranking of alternatives. A metric rationalizable SWF reports as an approximation of the unanimity consensus the relative ranking of any pair of alternatives as in the closest profile where individuals all agree on those alternatives, the closeness being measured with respect to a metric on profiles. Two notions of unanimity are in consideration: top unanimity on an alternative holds when individuals all agree that it is top ranked while pairwise unanimity on a pair occurs when individuals all prefer an alternative to another. Without strong requirements on metrics, characterizations provided in both cases show that metric rationalizations of SWFs are essentially equivalent to the Pareto principle for SWFs. Furthermore, two interesting classes of metric rationalizable SWFs–multi-valued scoring SWFs and pairwise scoring SWFs–are each uniquely identified by means of some appropriate and appealing properties on metrics among which decomposability, neutrality and monotonicity are known.     

The emergence of deontological codes in public administration

We study a model of the evolutionary selection of social standards of behavior in a large public organization, in terms of the propensity to bribery of the organization's rent-seeking officers. We examine several scenarios, allowing for the existence of various types of anti-corruption sanctioning mechanisms, for the role of pro-social, interiorized value systems, for the impact of informational costs on the viability of "informationally sophisticated" players. The conditions under which corruption is eventually eliminated or at least kept under control in the various scenarios are derived and discussed.     

The planning of headways in urban public transit

A basic issue in the planning of urban public transport is the determination of headways or inter-dispatch times. During each season, i.e. distinct time-period whose demand characteristics are constant, the following tradeoff must be considered. Dispatching too many vehicles on a route causes high operating costs, while too few vehicles may result in unsatisfactory levels of service. An appropriate policy on headways will help to balance resources between lines (routes) in peak-demand hours and will influence the total number of buses acquired by a transit company. Previous practice in industry usually bases the planning of headways upon satisfying service criteria on a most-congested segment. This approach reduces the problem from that of studying a route to that of a single segment (stop), but thereby fails to account for other important information about the line's characteristics. In this article, we develop two new service criteria which consider the line as a whole: (1) crowding-over-distance takes into account discomfort resulting from a vehicle carrying too many passengers, and the corresponding distance travelled; and (2) probability-of-failure, the frequency with which a waiting passenger fails to board due to lack of space. COD will be analyzed using simulation. POF will be related to a time-dependent Markov chain that is inhomogeneous in terms of distance along the route. Optimal headways are those which dispatch the smallest number of buses while meeting the particular service criterion. Models based on each of the two criteria are illustrated and applied to a number of routes of the Israeli transit company, DAN.The preparation of this paper was partially supported by the Natural Sciences and Engineering Research Council of Canada, Grant No. OGP 05292.     

The role of utility interdependence in public good experiments

A popular approach to explain over-contribution in public good games is based on the assumption that people care (either positively or negatively) about the utility of other participants. Over-contribution then is an outcome of utility maximization where utility depends on subjects’ own payoffs as well as on the payoffs of other players. In this paper, I study to what extent this assumption of utility interdependence is responsible for over-contribution. I design three treatments where subjects’ decisions cannot affect opponents’ payoffs and thus utility interdependence cannot explain cooperative behavior. The main result is that while average contribution in these treatments is below the benchmark it nonetheless stays well above zero. Even when no one benefits from subjects’ generosity the average contributions are as high as one third of the endowment and are only 25% below those in the benchmark level. This suggests that utility interdependence is not the main factor responsible for over-contribution. I would like to thank my dissertation advisor Shyam Sunder for his valuable suggestions that helped improve this paper. I am also grateful to Dan Levin, Ben Polak, Klaus Schmidt, Andrew Schotter, Anat Bracha, Danielle Catambay, Rodney Chan, two anonymous referees and the anonymous Associate Editor for their comments and suggestions. Participants of the 17th International Conference on Game Theory at Stony Brook University, 2006 ESA International Meeting and 10th Biennial Behavioral Decision Research in Management Conference provided a valuable feedback at earlier stages of the paper. Finally, I would like to thank the Whitebox Fellowship for its generous support of this study.     

The use of public randomization in discounted repeated games

This paper presents an example where the set of subgame-perfect equilibrium payoffs of the infinitely repeated game without public randomization is not convex, no matter how large the discount factor is. Also, the set of pure-strategy equilibrium payoffs is not monotonic with respect to the discount factor in this example. These results are in sharp contrast to the fact that the equilibrium payoff set is convex and monotonic if public randomization is available.     

Krause's model of opinion dynamics on isolated time scales

We analyze a bounded confidence model, introduced by Krause, on isolated time scales. In this model, each agent takes into account only the assessments of the agents whose opinions are not too far away from its own opinion. We show that the behavior of the model depends strongly on the graininess function μ: If μ takes values in the interval ]0,1], then our discrete time scale model behaves similarly to the classical one, but if μ takes values in ]1,+∞[, then the model has different properties. Simulations are performed to validate the theoretical results. Copyright © 2016 John Wiley & Sons, Ltd.