Through a get-out-the-vote experiment we study the effect of eight different statements related to ‘the calculus of voting’ and prospect theory on voter turnout in a high salience election with proportional representation of multiple parties. The treatments are randomly assigned to more than 60,000 first-time-voters and the treatments are distributed via a personal postal letter in a closed envelope. We find an overall effect of the letter to be 0.22 percentage points (std.error: 0.30), close to the findings from an U.S. context. The most effective of the treatments seems to be a letter including several arguments (ITT: 1.3 percentage points, std.error. 0.62). This supports the idea that citizens are more convinced when receiving multiple
arguments. There is no evidence of difference between versions of the letters emphasizing individual elements of the calculus of voting or whether the decision to vote was framed as a gain or a loss. We find limited heterogeneous effects though there is some tendency for the treatment effect to be somewhat larger for voters with low to middle turnout propensities