Eric S. Dickson

Dynamical Tide in Solar-Type Binaries

Circularization of late-type main-sequence binaries is usually attributed to turbulent convection, while that of early-type binaries is explained by resonant excitation of g-modes. We show that the latter mechanism also operates in solar-type stars and is at least as effective as convection despite inefficient damping of g-modes in the radiative core. The maximum period at which this mechanism can circularize a binary composed of solar-type stars in 1010 yr is as low as 3 days, if the modes are damped by radiative diffusion only and g-mode resonances are fixed, or as high as 6 days if one allows for evolution of the resonances and for nonlinear damping near inner turning points. Even the larger theoretical period falls short of the observed transition period by a factor of 2.

Cognition and Strategy: A Deliberation Experiment

A theory of deliberation must provide a plausible account both of individuals’ choices to speak or to listen and of how they reinterpret their own views in the aftermath of deliberation. We describe a game-theoretic laboratory experiment in which subjects with diverse interests speak or listen before voting over a common outcome. An important feature of our strategic setting is that introspective agents may, upon hearing an unpersuasive argument, update away from the speakers preferred position. While subjects are responsive to strategic incentives, they also deviate from Bayesian predictions by “overspeaking” when speech is likelier to alienate than persuade. Subjects thus come closer to the deliberative democratic ideal of a free exchange of arguments than equilibrium predictions suggest. We interpret evidence from subjects’ deliberative choices and policy votes in terms of a cognitive hierarchy among subjects, defined by differing abilities to grasp the strategic implications of different kinds of information.

Social Identity, Political Speech, and Electoral Competition

Much research in political science suggests that social identity can be an important factor in motivating behavior. If voters care about social identity, when will politicians find it in their interests to make group-based appeals? Do social identity concerns affect the policy platforms offered by candidates? In a model of political speech and electoral competition, in which voters care about both social identities and policy, we demonstrate that social identity concerns can lead to platform divergence even when the policy dimension is uncorrelated with identity. For example, policy-motivated politicians can employ identity rhetoric to obtain ‘slack’ in the policy dimension. Further, the need for candidates to resort to group-based appeals depends on such factors as the relative sizes of social groups; the policy preferences of group members; whether candidates care about policy and if so, their preferred policies; and the extent of individual identification with groups. The analysis demonstrates that social identity can have a striking impact on the strategic conduct of campaigns.

Social Identity, Electoral Institutions and the Number of Candidates

The existing empirical literature in comparative politics holds that social cleavages affect the number of candidates or parties when electoral institutions are “permissive.” However, this literature lacks a theoretical account of the strategic candidate entry and exit decisions that ultimately determine electoral coalitions under different institutions in plural societies. This paper incorporates citizen-candidate social identities into game-theoretic models of electoral competition under both plurality and majority-runoff electoral rules. Our theoretical results indicate that social group demographics can affect the equilibrium number of candidates, even in non-permissive systems. Under plurality rule, the relationship between social homogeneity and the effective number of candidates is non-monotonic and, contrary to the prevailing Duvergerian intuition, for some demographic configurations even the effective number of candidates cannot be near two. We find empirical patterns in cross-national data on presidential election results that are consistent with key intuitions derived from the formal model.

Enforcement and Compliance in an Uncertain World: An Experimental Investigation

Governments are charged with monitoring citizens’ compliance with prescribed behavioral standards and punishing noncompliance. Flaws in information available to enforcing agents, however, may lead to subsequent enforcement errors, eroding government authority and undermining incentives for compliance. We explore these concepts in a laboratory experiment. A “monitor” player makes punishment decisions after receiving noisy signals about other players’ choices to contribute to a public good. We find that the possibility of wrongly accusatory signals has a more deleterious effect on contribution levels than the possibility of wrongly exculpatory signals. We trace this across-treatment difference to a “false positives trap”: when members of a largely compliant population are sometimes incorrectly accused, some will be unjustly punished if enforcement power is employed, but non-compliant individuals will escape punishment if that power is abdicated. Either kind of error discourages compliance. An additional treatment demonstrates that the functioning of a given enforcement institution may vary, depending on its origins. We consider implications of our findings for theories of deterrence, fairness, and institutional legitimacy.

Rational Choice Epistemology and Belief Formation in Mass Politics

This article begins with a general discussion of the epistemology of rational choice, and argues that there are important questions in political science for which rational choice theory is not a particularly useful epistemic tool. It is further argued that part of the problem lies with the particular vision of methodological individualism that is inherent in the use of classical rational choice assumptions in game theoretic models. An alternative approach that endogenizes the way in which people form beliefs is then advocated as a potential solution to this problem, both as a means to expand the substantive reach of optimizing theories in political science, as well as a way of incorporating more psychological realism into models of political behavior. Two novel models allowing actors within political contexts to form beliefs in endogenous ways are then presented and discussed.

‘‘We Don’t Talk to Terrorists’’: On the Rhetoric and Practice of Secret Negotiations

Political actors sometimes make public commitments not to negotiate with adversaries whom they label as being beneath diplomacy. Such commitments are sometimes made even as they are being broken. Why do actors sometimes publicly denounce adversaries with whom they intend to negotiate? What effect does such prenegotiation rhetoric have on the prospects for successful negotiated settlements? In this paper, the authors present a novel game-theoretic model of conflict bargaining, in which actors can make public commitments not to negotiate before deciding whether to engage in secret negotiations with adversaries. The authors model such commitments as affecting actors’ audience costs; a denunciation increases an actor’s motivation to reach a negotiated settlement if negotiations are undertaken. Although such a decision weakens an actor’s bargaining power, in equilibrium actors sometimes publicly denounce their counterparts. The authors present and interpret equilibrium behavior in their model and discuss the implications of their results for future research.