How Many Citizens Have Already Voted? The Role of (Interim) Turnout Rate Polls in Elections

We examine the effect of interim turnout rate polls on elections within a costly voting model of a large electorate with private values and two alternatives. We consider that (i) one group of citizens votes before the rest and (ii) the individuals of the second group know the first group's turnoutrate—but not the vote tally—before they vote. The alternative that receives more votes in total is implemented. We show that the probability that each alternative is implemented under this voting procedure is the same as in one-round voting without interim turnout rate polls. An interpretation isthat these polls might not be distorting election outcomes. This observation can rationalize why some democracies report the ongoing turnout rate at several points in time during election day