Peer pressure in Parliament?

Study finds that current and former seating assignments impact how members of the European Parliament vote.

Whether you are out to dinner with friends or attending a conference with coworkers, your experience will be directly impacted by people in close proximity. For example, if everyone at your dinner table spends the night complaining about the food and service, you may leave unsatisfied even if you personally liked the restaurant. Similarly, if you are enjoying a motivational speaker’s presentation at a work conference but the coworkers sitting next to you act bored and impatient throughout the speech, you might decide you dislike the message, too.

Emir KamenicaIn their study “Peer Effects in Legislative Voting,” University of Chicago Booth School of Business Professor of Economics Emir Kamenica, University of Copenhagen’s Nikolaj Harmon, and Boston University’s Raymond Fisman explore the concept of peer influence in a formal setting: the European Parliament. The researchers’ choice of venue was strategic: the European Parliament has alphabetical seating assignments at both its Strasbourg and Brussels locations. Therefore, the experiment was controlled in the sense that members of parliament could not choose to sit with like-minded friends at sessions. In addition, since the group split its time between the Strasbourg and Brussels venues, the seating chart was a bit different at each location based on the size of the room and length of each row of seats.

After analyzing the voting data and accounting for the fact that politicians with similar last names might vote alike for reasons other than the seating arrangement – for example, because they are from the same country – the researchers conclude that seating assignments do in fact impact behavior.

“Sitting adjacently leads to a 13 percent reduction in the likelihood that two Members of the European Parliament (MEPs) from the same party differ in their vote,” said Kamenica.

In addition, the researchers determined that peer influence can have lasting effects on voting patterns. “We show that peer influence is persistent: [Members of the European Parliament] who have sat together in the past are less likely to disagree even on votes during which they are not seated adjacently,” said Kamenica. “This persistence might operate through altering peers’ allegiances or beliefs that influence future votes when the peers are no longer sitting next to one another.”

In other words, two parliament members who sit adjacently for a January vote in Strasbourg vote more similarly in Brussels in May, despite the fact that they no longer sit next to one another.

The findings have clear political implications, but can also apply to academia and other similar social settings. “Peer influence extends beyond mere parroting to impact beliefs or alliances,” they concluded.