Does Survey Participation Increase Voter Turnout? Re-examining the Hawthorne Effect in the Swedish National Election Studies

A Hawthorne effect found in election studies is that pre-election survey participation increases voter turnout. Using the Swedish National Election Studies, Granberg and Holmberg (1992) showed evidence in support of this effect. However, their findings have been criticized and more recent studies have failed to find any treatment effect of pre-election survey participation (cf. Mann 2005). This study re-examines an updated version of Granberg and Holmberg's time-series cumulative data file covering eight additional election studies (for a total of 14 election studies from 1960 to 2010). These studies have an experimental component, since half of the sample was randomly assigned to be interviewed before the election and the other half after the election. By comparing validated turnout in the pre-election sample with the post-election sample, it is possible to estimate the causal effect of survey participation on voter turnout. The results show that participating in the pre-election survey indeed has a significant and positive effect on voter turnout. Moreover, this article evaluates whether the treatment effect is unevenly distributed in the population. Results show that citizens with a low propensity to vote are more affected by taking part in election studies than citizens with a high propensity to vote. The study also estimates the long-term effects of survey participation. Results show that participating in an election survey can have significant effects on voter turnout several years later.