Competition & turnout: the majority run-off as a natural experiment

Run-off elections offer certain advantages for the study of political behavior over other electoral systems. This paper exploits the fact that run-off elections resemble a natural experiment to study the effects of competitiveness on voter turnout. The literature offers several explanations of the determinants of voter turnout. In run-off elections most of these factors can be assumed to be constant between the two ballots. Run-off elections, thus, provide an opportunity to evaluate the insights offered by rational choice theories of voter turnout. The results of the first ballot inform voters about the competitiveness of the race, which influences their propensity to vote on the second ballot. I derive several hypotheses about voter turnout in multi-candidate run-off elections from a simple theoretical framework and test them using data on the French legislative elections of 1997 and 2002. The results indicate competitiveness has a strong effect on voter turnout.