This article considers manipulation of collective choice — in such environments, a potential alternative is powerful only to the degree that its introduction can affect the collective decision. Using the Banks set (Banks, 1985), we present and characterize alternatives that can, and those that can not, affect sophisticated collective decision-making. Along with offering two substantive findings about political manipulation and a link between our results and Riker's concept of heresthetic, we define a new tournament solution concept that refines the Banks set, which we refer to as the heresthetically stable set.

Remarkable levels of coordination are observed among social agents; yet the exact mechanisms by which such agents coordinate are not well understood. Here we examine the role of communication in achieving coordination-in particular, does endowing agents with the ability to communicate lead to more favorable outcomes? To pursue this question we employ an adaptive model of strategically communicating agents (Miller et al. [7]) playing the Stag Hunt game.We find that communication plays a key role in the ability of agents to reach and maintain superior coordination. In the absence of communication, agents tend to get trapped at the inferior coordination point. However, once agents reach a particular strategic threshold, sending even a priori meaningless messages serves to increase the likelihood that the population will coordinate on the superior outcome. While the system spends the majority of its time with well-coordinated behavior, it is not static-such periods are often punctuated by brief transitions in which the system switches to the alternative coordination point. We analyze the various mechanisms that account for this dynamic behavior and find that there are a few critical pathways by which the system transitions from one coordination point to another. Communication plays a critical, yet short-lived, role in one key pathway.Our analysis suggests that giving agents the ability to communicate even a priori meaningless messages may promote the emergence of a rich, and often robust, "ecology" of behaviors that allows agents to achieve new, and in this case superior, outcomes.

We present a formal model of international bargaining between two states in which one government must negotiate with a domestic opposition faction to secure tax revenue for military spending. The model examines how robust the international order is to domestic political crises that activate a stark trade-off to a governing coalition. Namely, offering fiscal relief to stave off domestic revolution can simultaneously undermine the larger international political order by facilitating military spending that can, under some circumstances, result in sizable shifts in the relative distribution of military power between states. We find that two key domestic conditions influence the likelihood of preventive war: the distribution of income within the state's economy and the relative economic stake that opposition groups possess in international settlements. Patrick J. McDonald is an associate professor of Government at the University of Texas at Austin. His current research examines systemic theories of international politics.

We extend classical ideal point estimation to allow voters to have different preferences when voting in different domains—for example, when voting on agricultural policy than when voting on defense policy. Our scaling procedure results in estimated ideal points on a common scale. As a result, we are able to directly compare a member’s revealed preferences across different domains of voting (different sets of motions) to assess if, for example, a member votes more conservatively on agriculture motions than on defense. In doing so, we are able to assess the extent to which voting behavior of an individual voter is consistent with a uni-dimensional spatial model—if a member has the same preferences in all domains. The key novelty is to estimate rather than assume the identity of “stayers”—voters whose revealed preference is constant across votes. Our approach offers methodology for investigating the relationship between the basic space and issue space in legislative voting (Poole 2007). There are several methodological advantages to our approach. First, our model allows for testing sharp hypotheses. Second, the methodology developed can be understood as a kind of partial-pooling model for item response theory scaling, resulting in less uncertainty of estimates. Related, our estimation method provides a principled and unified approach to the issue of “granularity” (i.e., the level of aggregation) in the analysis of roll-call data (Crespin and Rohde 2010; Roberts et al. 2016). We illustrate the model by estimating U.S. House of Representatives members’ revealed preferences in different policy domains, and identify several other potential applications of the model including: studying the relationship between committee and floor voting behavior; and investigating constituency influence and representation.

Roll call data are widely used to assess legislators' preferences and ideology, as well as test theories of legislative behavior. In particular, roll call data is often used to determine whether the revealed preferences of legislators are affected by outside forces such as party pressure, minority status or procedural rules. This paper describes a Bayesian hierarchical model that extends existing spatial voting models to test sharp hypotheses about differences in preferences the using posterior probabilities associated with such hypotheses. We use our model to investigate the effect of the change of party majority status during the 107 th U.S.Senate on the revealed preferences of senators. This analysis provides evidence that change in party affiliation might affect the revealed preferences of legislators, but provides no evidence about the effect of majority status on the revealed preferences of legislators.