Information and Strategic Voting: Coordination in a Small World
Emily Clough

     The relationship that information plays in shaping political decisions and outcomes has long been an area of interest to political scientists. Using a game theoretic model of strategic voting, Cox (1997) suggests one way that information may have a profound impact on voters’ ability to coordinate on M+1 parties in a M-seat district: polls, or some other source of public information about the relative standing of the candidates, must be available in order to help voters understand which candidates are likely to win. While there are a number of situations in which these conditions are filled, it is possible to think of a number in which they are not: historically, for instance, or in developing countries. What happens in situations in which these conditions are not filled? Can voters coordinate effectively? How does this affect the shape of the party system? One way of looking at this problem formally is to create a model using an agent-based approach; this approach allows the modeler to specify informational conditions with greater
flexibility than a game theoretic model. This paper presents the results from an agent-based model in which voters gather information about the voting tendencies of their neighbors in a network. The network is a “small world” network, i.e. it is highly clustered and has a short characteristic path length (Watts 1999); in other words, social networks are clustered, but there are a few key agents who provide connections across these clusters, making the length of the path between any two agents fairly short. Empirically, we could think of this as a situation in which there is a great deal of segregation of communities, but a few people who are still able and willing to communicate between these communities; it is possible to think of a number of concrete instances where this is the case. Watts (1999) demonstrated that employing these networks can have a profound impact on the outcomes of models and provide a better understanding of how information is shared and spread; however, political scientists have not
really begun to integrate these networks into their models. Using a small world network to model coordination through strategic voting gives us a better sense of how coordination may occur when polls are not available.