The marginal voter's curse

An intuitive explanation for voter abstention is that a voter is uncertain which policy or candidate to vote for, and so defers to the rest of the electorate to make the decision. In majoritarian elections this has been formally modeled as a strategic response to the swing voter's curse, which arises because the rare event of a pivotal vote conveys substantial information. In electoral systems other than majority rule, however, the standard pivotal voting calculus may not apply. This paper analyzes one such system, namely proportional representation, where additional votes continue to push the policy outcome in one direction or the other. A new strategic incentive for abstention arises in that case, to avoid the marginal voter's curse of pushing the policy outcome in the wrong direction. Intuitively, conditioning on the rare event of a pivotal vote might seem to have a greater impact on behavior, but the marginal voter's curse actually presents a larger disincentive for voting than the swing voter's curse. This and other predictions of the model are confirmed empirically by a series of laboratory experiments.