Costly information acquisition. Part I: better to toss a coin?

In a common-values election with two candidates voters receive a signal about which candidate is superior. They can acquire information that improves the precision of the signal. Electors differ in their information acquisition costs. For large electorates a non negligible fraction of voters acquires information, but the quantity of informed voters and the quality of acquired information decline so fast that information aggregation fails to obtain.Costly Information Acquisition, Condorcet Jury Theorem.

Beyond Condorcet: Optimal Aggregation Rules Using Voting Records

In certain judgmental situations where a “correct” decision is presumed to exist, optimal decision making requires evaluation of the decision-maker's capabilities and the selection of the appropriate aggregation rule. The major and so far unresolved difficulty is the former necessity. This paper presents the optimal aggregation rule that simultaneously satisfies these two interdependent necessary requirements. In our setting, some record of the voters' past decisions is available, but the correct decisions are not known. We observe that any arbitrary evaluation of the decision-maker's capabilities as probabilities yields some optimal aggregation rule that, in turn, yields a maximum-likelihood estimation of decisional skills. Thus, a skill-evaluation equilibrium can be defined as an evaluation of decisional skills that yields itself as a maximum-likelihood estimation of decisional skills. We show that such equilibrium exists and offer a procedure for finding one. The obtained equilibrium is locally optimal and is shown empirically to generally be globally optimal in terms of the correctness of the resulting collective decisions. Interestingly, under minimally competent (almost symmetric) skill distributions that allow unskilled decision makers, the optimal rule considerably outperforms the common simple majority rule (SMR). Furthermore, a sufficient record of past decisions ensures that the collective probability of making a correct decision converges to 1, as opposed to accuracy of about 0.7 under SMR. Our proposed optimal voting procedure relaxes the fundamental (and sometimes unrealistic) assumptions in Condorcet celebrated theorem and its extensions, such as sufficiently high decision-making quality, skill homogeneity or existence of a sufficiently large group of decision makers.

Market concentration and the likelihood of financial crises

According to theory, market concentration affects the likelihood of a financial crisis in different ways. The “concentration-stability” and the “concentrationfragility” hypotheses suggest opposing effects operating through specific channels. Using data of 160 countries for the period 1970-2007, this paper empirically tests these indirect effects of financial market structure. We set up a simultaneous system in order to jointly estimate financial stability and the relevant channel variables as endogenous variables. Our findings provide support for the assumption of channel effects in general and both the concentrationstability and the concentration-fragility hypothesis in particular. The effects are found to vary between high and low income countries.Market Concentration, Financial Crisis, Systemic Crisis

Exploring Russian Cyberspace: Digitally-Mediated Collective Action and the Networked Public Sphere

This paper summarizes the major findings of a three-year research project to investigate the Internet's impact on Russian politics, media and society. We employed multiple methods to study online activity: the mapping and study of the structure, communities and content of the blogosphere; an analogous mapping and study of Twitter; content analysis of different media sources using automated and human-based evaluation approaches; and a survey of bloggers; augmented by infrastructure mapping, interviews and background research. We find the emergence of a vibrant and diverse networked public sphere that constitutes an independent alternative to the more tightly controlled offline media and political space, as well as the growing use of digital platforms in social mobilization and civic action. Despite various indirect efforts to shape cyberspace into an environment that is friendlier towards the government, we find that the Russian Internet remains generally open and free, although the current degree of Internet freedom is in no way a prediction of the future of this contested space

Computational Aspects of Nearly Single-Peaked Electorates

Manipulation, bribery, and control are well-studied ways of changing the outcome of an election. Many voting rules are, in the general case, computationally resistant to some of these manipulative actions. However when restricted to single-peaked electorates, these rules suddenly become easy to manipulate. Recently, Faliszewski, Hemaspaandra, and Hemaspaandra studied the computational complexity of strategic behavior in nearly single-peaked electorates. These are electorates that are not single-peaked but close to it according to some distance measure. In this paper we introduce several new distance measures regarding single-peakedness. We prove that determining whether a given profile is nearly single-peaked is NP-complete in many cases. For one case we present a polynomial-time algorithm. In case the single-peaked axis is given, we show that determining the distance is always possible in polynomial time. Furthermore, we explore the relations between the new notions introduced in this paper and existing notions from the literature.Comment: Published in the Journal of Artificial Intelligence Research (JAIR). A short version of this paper appeared in the proceedings of the Twenty-Seventh AAAI Conference on Artificial Intelligence (AAAI 2013). An even earlier version appeared in the proceedings of the Fourth International Workshop on Computational Social Choice 2012 (COMSOC 2012

Understanding Political Agreements and Disagreements: Evidence from the 2022 French Presidential Election

Since the seminal works of Condorcet and Borda, social choice theory has explored how to aggregate individual preferences into collective decisions. Yet, social choice theory has focused primarily on identifying winners in elections involving few candidates, leaving questions about direct participation on multiple issues relatively unexplored. Here we analyze data collected in a direct participation experiment where people built their own government programs using 120 proposals from the candidates of the 2022 French presidential. We find that in this setting it is useful to introduce a measure of "divisiveness," which can be constructed for any voting rule, is orthogonal to them, and helps identify polarizing proposals. We show that divisiveness captures fragmentation across multiple dimensions (sex, age, political orientation, and urban-rural divide) and explore some of its axiomatic properties. These results suggest divisiveness is a relevant aggregate in direct forms of participation.Comment: 23 pages main manuscript with 8 figures. 25 pages of supplementary materia

Fragility, Aid, and State-building

Fragile states pose major development and security challenges. Considerable international resources are therefore devoted to state-building and institutional strengthening in fragile states, with generally mixed results. This volume explores how unpacking the concept of fragility and studying its dimensions and forms can help to build policy-relevant understandings of how states become more resilient and the role of aid therein. It highlights the particular challenges for donors in dealing with ‘chronically’ (as opposed to ‘temporarily’) fragile states and those with weak legitimacy, as well as how unpacking fragility can provide traction on how to take ‘local context’ into account. Three chapters present new analysis from innovative initiatives to study fragility and fragile state transitions in cross-national perspective. Four chapters offer new focused analysis of selected countries, drawing on comparative methods and spotlighting the role of aid versus historical, institutional and other factors. It has become a truism that one-size-fits-all policies do not work in development, whether in fragile or non-fragile states. This is should not be confused with a broader rejection of ‘off-the-rack’ policy models that can then be further adjusted in particular situations. Systematic thinking about varieties of fragility helps us to develop this range, drawing lessons – appropriately – from past experience. This book was originally published as a special issue of Third World Quarterly, and is available online as an Open Access monograph at https://www.taylorfrancis.com/books/e/9781351630337