We propose a model where voters are embedded in a social network. Each
voter observes the ballots of her neighbors in the network, from which
she infers the likely outcome of the election. Each voter may then
revise her vote strategically, to maximize her expected utility. Our
work focuses on plurality voting, where strategic voting is a major
concern. We show that in practice, strategization increases with voter
knowledge, yet can improve the social welfare for the population.
Real world social networks exhibit a property called homophily;
sometimes called "The Echo Chamber Effect", which is the tendency for
friends to have similar ideologies. We find that homophily dampens the
benefits of strategization, and correspondingly, lowers the frequency
of its occurrence. This effect may contribute to the low number of
strategic voters observed in real world elections. Additionally,
strategization may lead to the elimination of less popular candidates,
as voters revise their votes to less preferred but more hopeful
candidates. This phenomenon is known as Duverger's Law in political
science, and we show that it does not hold in certain network
structures.