Deliberation, Leadership and Information Aggregation

American Economic Review, 2008

This dissertation consists of three related chapters. The first chapter, which is written jointly with Lones Smith presents a dynamic model of deliberation by two privately informed individuals. Even by assuming the coarsest possible language to communicate information among members, it is shown that the decision is `almost instantaneous' when individuals have identical objectives. Despite the coarse syntax, the model also predicts that information aggregation can be quite effective. The second chapter asks the question under what circumstances can a static voting mechanism aggregate dispersed information of committee members. I argue that whenever the voters are able to cast multiple votes, the quality of the joint decision increases. However, voting mechanisms are intrinsically additive ways of aggregating private information. This, naturally, is not a binding constraint if the private information is conditionally independent. However, if the `meaning' of the private infor...

University of Copenhagen Economics Working Paper No. 14-18, 2014

We investigate experimentally the effects of corrupt experts on information aggregation in committees. We find that non-experts are significantly less likely to delegate through abstention when there is a probability that experts are corrupt. Such decreased abstention, when the probability of corrupt experts is low, actually increases information efficiency in committee decision-making. However, if the probability of corrupt experts is large, the effect is not sufficient to offset the mechanical effect of decreased information efficiency due to corrupt experts. Our results demonstrate that the norm of "letting the expert decide" in committee voting is influenced by the probability of corrupt experts, and that influence can have, to a limited extent, a positive effect on information efficiency.

Public Choice, 2018

This paper studies the collective decision-making processes of voters who have heterogeneous levels of rationality. Specifically, we consider a voting body consisting of both rational and sincere voters. Rational voters vote strategically, correctly using both their private information and the information implicit in other voters' actions to make decisions; sincere voters vote according to their private information alone. We first characterize the conditions under which the presence of sincere voters increases, reduces, or does not alter the probabilities of making correct collective decisions. We also discuss how the probabilities change when the incidence of sincere voters in the population varies. We then characterize the necessary and sufficient condition under which informational efficiency can be achieved when sincere voters coexist with rational voters. We find that when sincere voters are present, supermajority rules with high consensus levels are not as desirable as they are in rational voting models, as informational efficiency fails under such voting rules.

2006

There has been recent interest in the limit properties of voter turnout in costly voting models (see, for instance Taylor and Yildirim (2005)). However, the focus of this work has been on the so-called “private values” case— voters privately know which candidate they prefer and the only strategic decision is whether or not to go to the polls. A related literature pertains to the “common values”case— voter preferences are determined by the realization of an unknown “state of nature” and each voter receives a noisy signal about the state. This line of research has focused on how di¤erences in voting rules lead to di¤erences in informational e¢ ciency (see Feddersen and Pesendorfer (1998)). However, this class of models does not consider costs of voting. In this paper, we analyze the common values case under costly voting. In our basic model, voters each have privately known and independently and identically distributed voting costs. In a variation of the model, in Section 3.2, we anal...

2008

We consider a group or committee that faces a binary decision under uncertainty. Each member holds some private information. Members agree which decision should be taken in each state of nature, had this been known, but they may attach different values to the two types of mistake that may occur. Most voting rules have a plethora of uninformative equilibria, and informative voting may be incompatible with equilibrium. We analyze an anonymous randomized majority rule that has a unique equilibrium. This equilibrium is strict, votes are informative, and the equilibrium implements the optimal decision with probability one in the limit as the committee size goes to infinity. We show that this also holds for the usual majority rule under certain perturbations of the behavioral assumptions: (i) a slight preference for voting according to one's conviction, and (ii) transparency and a slight preference for esteem. We also show that a slight probability for voting mistakes strengthens the incentive for informative voting.

Economics and Philosophy, 2015

We present a model of collective decision making in which aggregation and deliberation are treated simultaneously. In our model, individuals debate in a public forum and potentially revise their judgements in light of deliberation. Once this process is exhausted, a rule is applied to aggregate post-deliberation judgements in order to make a social choice. Restricting attention to three alternatives, we identify conditions under which a democracy is "truth-revealing". This condition says that the deliberation path and the aggregation rule always * Financial support from the Irish Research Council for the Humanities and Social Sciences, the Spanish Ministry of Science and Innovation through MICINN/FEDER grants ECO2010-21624 and ECO2010-14929, and the NUI Galway Millennium Fund is gratefully acknowledged. We are grateful for comments received at a Choice Group seminar at LSE and also those received at a seminar at the Université de Caen. In particular, we would like to thank

2020

Committee protocols typically involve deliberations in which committee members try to influence and convince each other regarding the “right” choice. Such deliberations do not involve only information exchange, but their aim is also to affect the preferences and the votes of other members. This aspect of social influence and committee deliberation is the focus of this paper. Using a model of social influence we demonstrate how deliberation procedures affect the voting outcome and how different protocols of consultation by committees’ chairs may affect the chairs’ final decisions. We then analyze the ability of a “designer” to control the deliberation protocol and to manipulate the deliberation procedure to increase the probability that the outcome he favors will be selected.

The Review of Economic Studies, 2013

This paper analyzes participation and information aggregation in a common-value election with continuous private signals. In equilibrium, some citizens ignore their private information and abstain from voting, in deference to those with higher-quality signals. Even as the number of highly-informed peers grows large, however, citizens with only moderate expertise continue voting, so that voter participation remains at realistic levels (e.g. 50% or 60%, for simple examples). The precise level of voter turnout, along with the margin of victory, are determined by the distribution of expertise. Improving a voter's information makes her more willing to vote, consistent with a growing body of empirical evidence, but makes her peers more willing to abstain, providing a new explanation for various empirical patterns of voting. Equilibrium participation is optimal, even though the marginal voter may have very little (e.g. below-average) expertise, and even though non-voters'information is not utilized.

2021

Recent developments in blockchain technology have made possible greater progress on secure electronic voting, opening the way to better ways of democratic decision making. In this paper we formalise the features of ``liquid democracy'' which allows voters to delegate their votes to other voters, and we explore whether it improves information aggregation as compared to direct voting. We consider a two-alternative setup with truth-seeking voters (informed and uninformed) and partisan ones (leftists and rightists), and we show that delegation improves information aggregation in finite elections. We also propose a mechanism that further improves the information aggregation properties of delegation in private information settings, by guaranteeing that all vote transfers are from uninformed to informed truth-seeking voters. Delegation offers effective ways for truth-seeking uninformed voters to boost the vote-share of the alternative that matches the state of the world in all cons...