Altruism theory of voting

Since the failure of standard rational choice models—which assume voters have "selfish" preferences—to explain voter turnout in large elections, public choice economists and social scientists have increasingly turned to altruism as a way to explain why rational individuals would choose to vote despite its apparent lack of individual benefit, explaining the paradox of voting. The theory suggests that individual voters do, in fact, derive personal utility from influencing the outcome of elections in favor of the candidate that they believe will implement policies for the greater good of the entire population.

The rational calculus of voting

The "selfish" rationale for voting

The standard model of voter calculus was articulated by Riker and Ordeshook in their 1968 article "A Theory of the Calculus of Voting" in The American Political Science Review. The basic utility hypothesis for the calculus of voting they gave was:

R = (BP) − C

Where B is the expected differential utility a voter personally receives from his preferred candidate winning; P is the probability of the voter bringing about B (that is, turning the election for his preferred candidate); C is the individual's cost of voting in the election; and R is the individual's expected reward from voting. If R > 0, then the expected utility of voting outweighs its costs, and it is reasonable to vote. But if R ≤ 0, the costs outweigh the benefits and a strictly rational individual would not be expected to vote.

Because P, the probability of any one vote determining the outcome, is extremely small for any large election, the expected benefits of voting under the traditional rational choice model is always roughly equal to zero. This leads to the so-called paradox of voting, in which rational choice models of voter behavior predict tiny turnouts which simply do not occur. In all democracies, voter turnout exceeds what the basic rational choice models predict.

Expressive versus instrumental voting

Because simple selfishness cannot explain why large numbers of people consistently choose to vote, Riker and Ordeshook introduced another term to the equation, D, to symbolize the personal or social benefits conferred by the act of voting itself, rather than by affecting the outcome of the election.

R = (BP) − C + D

This drew a distinction between expressive voting, intended only to signal support or demonstrate civic responsibility, and instrumental voting, intended to actually change the outcome. The benefits here did not come from actually influencing the election, but rather from the social payoffs of participating in it. Because the term BP was assumed to be zero, D was presumed to be the only important factor in determining elections.

The "altruistic" rationale for voting

Because of the multitude of different and contradictory definitions of expressive voting, recently another effort by political scientists and public choice theorists has been made to explain voting behavior with reference to instrumental benefits received from influencing the outcome of the election. If voters assumed to be rational but also to have altruistic tendencies and some preference for outcomes enhancing the social welfare of others, they will reliably vote in favor of the policies they perceive to be for the common good, rather than for their individual benefit.

In his paper "Altruism and Turnout," James H. Fowler explained how the altruistic theory modified the calculus of voting:

Scholars incorporate altruism into the traditional calculus of voting model by assuming that a citizen also cares about the benefits that others secure from the preferred outcome (Edlin, Gelman, and Kaplan 2006; Jankowski 2002, 2004). Under this assumption, B is a function not only of direct benefits to oneself BS, but to the N other people affected by the outcome of the election who would gain an average benefit BO if the citizen’s preferred alternative won. It also depends on how much the citizen cares about benefits to others, which is labeled a for altruism.

These assumptions transform the calculus of voting to P(BS + aNBO) > C.

...There is by now a substantial literature in economics, sociology, biology, psychology, and political science yielding evidence that human beings are also motivated by the welfare of others (Fehr and Fischbacher 2003; Monroe 1998; Piliavin and Charng 1990). Specifically, people frequently engage in acts of altruism by choosing to bear costs in order to provide benefits to others.

Essentially, voters behave altruistically by absorbing the cost of voting in order to provide society with the benefits of their preferred policy, although the expected reward of voting under this model is greater than zero (and thus still a rational decision) because of voters' altruistic social preferences. Edlin, et al., found in their study of altruistic behavior among voters,

... [F]or an individual with both selfish and social preferences, the social preferences will dominate and make it rational for a typical person to vote even in large elections;(2) to show that rational socially-motivated voting has a feedback mechanism that stabilizes turnout at reasonable levels (e.g., 50% of the electorate)...

Their findings suggest that in a large election, altruistic preferences will trump selfish tendencies, thus encouraging a stable voter turnout that closely mirrors the observed rate in western democracies.