Aggregation of endogenous information in large elections

We study aggregation of information when voters can collect information of different precision, with increased precision entailing an increasing marginal cost. In order to properly understand the incentives to collect information we introduce another dimension of heterogeneity: on top of the ideological dimension we allow for different levels of intensity in preferences. Contrary to traditional models of endogenous information, in equilibrium, there are voters collecting information of different qualities. After characterizing all symmetric Bayesian equilibria in pure strategies for arbitrary rules of election and fairly general distribution of types. We study information aggregation in symmetric electorates and show that information aggregates even when voters collect information of different qualities

Power Brokers: Middlemen in Legislative Bargaining

We consider a model of decentralized bargaining among three parties. Parties meet one-on-one after being randomly matched, and can sell or buy votes to one another. The party with a majority of the votes can decide to implement its preferred policy or extend negotiations to capture additional rents. We provide necessary and sufficient conditions for the existence of an equilibrium in which a party acts as an intermediary, transferring resources and voting rights among parties that wouldn't negotiate directly with one another. These conditions are generic, do not require special frictions, and include `well-behaved' (i.e., single-peaked) preference profiles

The Condorcet Jur(ies) Theorem

Should two issues be decided jointly by a single committee or in separately by different committees? Similarly, should two defendants be tried together in a joint trial or tried separately in severed trials? Multiplicity of issues or defendants introduces novel strategic considerations. As in the standard Condorcet Jury Theorem, we consider large committees with common values and incomplete information. Our main result is that the joint trial by a single committee can aggregate information if and only if the severed trials by separate committees can aggregate information. Specifically, suppose that either for the joint trial or for the severed trials there exists an sequence of equilibria that implements the optimal outcome with probability approaching one as the number of voters goes to infinity. Then a sequence of equilibria with similar asymptotic efficiency exists for the other format. Thus, the advantage of either format cannot hinge on pure information aggregation with many signals

Helioseismic and Magnetic Imager observations of linear polarization from a loop prominence system

White-light observations by the Solar Dynamics Observatory's Helioseismic and Magnetic Imager of a loop-prominence system occurring in the aftermath of an X-class flare on 2013 May 13 near the eastern solar limb show a linearly polarized component, reaching up to $\sim$20% at an altitude of $\sim$33 Mm, about the maximal amount expected if the emission were due solely to Thomson scattering of photospheric light by the coronal material. The mass associated with the polarized component was 8.2$\times$10$^{14}$ g. At 15 Mm altitude, the brightest part of the loop was 3(+/-0.5)% linearly polarized, only about 20% of that expected from pure Thomson scattering, indicating the presence of an additional unpolarized component at wavelengths near Fe I (617.33 nm), probably thermal emission. We estimated the free electron density of the white-light loop system to possibly be as high as 1.8$\times$10$^{12}$ cm$^{-3}$.Comment: 9 pages, 5 figure

Approval voting and scoring rules with common values

We compare approval voting with other scoring rules for environments with common values and private information. For finite electorates, the best equilibrium under approval voting is superior to plurality rule or negative voting. For large electorates, if any scoring rule yields a sequence of equilibria that efficiently aggregates information, then approval voting must do so as well