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The heat is on

21 June 2017

The article at a glance

Higher temperatures boost voter turnout and helps the incumbent party, finds study based on temperature, turnout and results in each US state …

Category: Insight

Higher temperatures boost voter turnout and helps the incumbent party, finds study based on temperature, turnout and results in each US state for presidential elections between 1960 and 2016.

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Elections have long been studied by pollsters, pundits and others who measure the political climate. A new study co-authored at Cambridge Judge Business School adds another element to the political mix – the real climate in terms of change in temperature.

A paper published this month in the journal Frontiers in Psychology finds that changes in temperature and voter turnout are positively related, and such a positive change in temperature helps the incumbent party. The study is based on temperature, voter turnout and voting results in all 50 US states for every presidential election between 1960 and 2016.

“It is often mentioned that ‘the heat is on’ during presidential campaigns, and our findings indeed clarify that temperature matters when it comes to actual voting,” the study says.

It’s all related to what’s known in psychology circles as “excitation transfer theory” – which holds that hot temperatures lead to increased arousal that translates to a readiness to respond behaviourally, and such arousal can increase both antisocial and prosocial behaviour.

Many previous studies have found that hot temperatures can be associated with antisocial behaviour such as assaults, as well as negative political behaviour such as riots. And while some prior studies have found a link between hot temperature and some prosocial behaviour (such as leaving generous tips to waiters), the new study goes a step farther to find a link between higher temperature and positive political behaviour.

David De Cremer
Professor David De Cremer

“We found that every one degree centigrade temperature increase on Election Day boosted voter turnout by 0.14 per cent,” said study co-author David De Cremer, KPMG Professor of Management Studies at Cambridge Judge Business School.

“In terms of the effect on incumbents, we found that although the higher voter turnout caused by hotter temperatures harms incumbents – because people being so motivated to vote want political change – this was outweighed by the advantage to incumbents from the positive link between temperature and votes for the incumbent.”

The study concludes: “The negative indirect effect of temperature for the incumbent party is fully compensated by its even stronger, positive direct effect. This result indicates that higher temperatures make the majority of voters increasingly lenient toward the party in power.”

The study focuses on change in temperature for each state (based on a weather station close to the state’s population centre) from Election Day to Election Day, rather than absolute temperature (as some states such as Hawaii and California are naturally warmer than others).

The study adjusts for nine variables such as presidential approval ratings, party control of Congress, whether the incumbent is eligible for re-election, and whether the incumbent was first elected as president (Lyndon Johnson and Gerald Ford were elevated from the vice presidency).

The study’s authors say that the findings add to understanding of “non-ideological and even non-rational factors that influence voting behaviour”.

The study – entitled “When the Heat Is On: The Effect of Temperature on Voter Behavior in Presidential Elections” – is co-authored by Jasper Van Assche, Alain Van Hiel, Jonas Stadeus and Arne Roets of Ghent University in Belgium, Brad Bushman of Ohio State University, and David De Cremer of Cambridge Judge Business School.