Voting, fast and slow: Ballot order and likeability effects in the five-star movement’s 2012 online primary election

We document ballot order effects in the 2012 Parlamentarie, the online primary election held by the Italian Five-star Movement to select the candidate Members of Parliament in the 2013 Italian general elections. We show that candidates appearing towards the top of the screen systematically ranked higher in preferences. This effect holds controlling for candidates’ socio-demographic features. We also show that the number of competing candidates moderates ballot order effects, with a stronger penalty for candidates appearing at the bottom of the page in more crowded competitions. Finally, we show the influence of candidates’ likeability. Our results confirm for the first time that ballot order effects and likeability effects, already documented in traditional paper-based elections, are also found in online set-ups. We conclude by highlighting how the online medium, if properly leveraged, has the potential to reduce the influence of such biases.