Welcome to the latest in my occasional series highlighting interesting findings from academic research. Today, “The Minimal Persuasive Effects of Campaign Contact in General Elections: Evidence from 49 Field Experiments”* which, as the title implies, finds that campaign contact with voters doesn’t seem to make much of a difference to election results. The full story, however, is rather more complicated.
First, the broad picture: the pattern in the UK is – even including 2017 – that the party ahead well in advance of a general election nearly always goes on to win the election. In that sense, you can fall asleep at Christmas, wake up the day after a general election and not have that much difficulty explaining who won and why. Even in 2017 the campaign didn’t change who was ahead and who was in Downing Street. More on that in my chapter for More Sex, Lies and the Ballot Box and in m book, Bad News.
Even in the US with the fabled Obama campaigns, the evidence of them actually switching votes is rather muted and more systematic research for US elections also finds that pre-campaign factors dominate.
Within that broad picture, however, the UK experience has been that for individual constituencies, what happens in those final months, weeks and even days can make a difference to who wins specific seats. Political campaigning, even in the last few weeks, can still matter.
On to this new research then, which found:
We argue that the best estimate of the effects of campaign contact and advertising on Americans’ candidates choices in general elections is zero. First, a systematic meta-analysis of 40 field experiments estimates an average effect of zero in general elections. Second, we present nine original field experiments that increase the statistical evidence in the literature about the persuasive effects of personal contact 10-fold. These experiments’ average effect is also zero. In both existing and our original experiments, persuasive effects only appear to emerge in two rare circumstances. First, when candidates take unusually unpopular positions and campaigns invest unusually heavily in identifying persuadable voters. Second, when campaigns contact voters long before election day and measure effects immediately — although this early persuasion decays.
Before you rush to put up your campaigning feet until this May’s round of elections are over, some caveats and context apply.
First, this research is only for American general elections. How far that generalises to other types of elections, and to other countries, is very much up for debate. Especially given that the particularly polarised nature of American two-party politics is very different from that in other countries. The rise of a new or previously fringe populist party which has been seen in many other countries, for example, has not happened in the US. How American politics work is not the same as how politics works.
Second, and building on this point about polarisation, the research found that, “Campaigns are able to have meaningful persuasive effects in primary and ballot measure campaigns, when partisan cues are not present”. That is suggestive of campaigning also being effective in contests with partisan cues but taking place in less polarised political systems.
Third, even in polarised context with partisan cues, the research doesn’t rule out all campaign effects given its narrow focus:
Our argument is not that campaigns, broadly speaking, do not matter. For example, candidates can determine the content of voters’ choices by changing their positions, strategically revealing certain information, and affecting media narratives— dynamics which are outside the scope of our analysis but could be affected by advertising (Holbrook 1996; Jacobson 2015; Johnston, Hagen and Jamieson 2004; Sides and Vavreck 2013). Campaigns can also effectively stimulate voter turnout (e.g., Gerber and Green 2000; Green, McGrath and Aronow 2013). Our argument is not that campaigns do not influence general elections in any way, but that the direct persuasive effects of their voter contact and advertising in general elections are essentially zero.
Fourth, the research is about a predominantly two-party political system. In a multi-party system that uses first past the post, as in the UK for many elections, then the need to be credible as a potential winner and hence to pick up tactical votes and the like could result in voter contact having an impact. A canvasser on your doorstep may say, ‘this party has a chance here’ in a way that is not relevant to a choice between Democrat and Republican in the US.
What conclusion to draw from this? For those interested in British politics, it’s a methodological rather than an empirical conclusion. The reasons above are good reason not to assume that the US general election finding necessarily applies to British elections, especially given the research in Britain showing an impact of constituency campaigning, such as by comparing activity and expenditure levels.
Even so, there is a useful methodological point. Those US studies being critiqued by this new study were generally carried out skillfully. It’s a reminder of how easy it is to be misled by a little bit of analysis, especially if the conclusions suit what you wish to be true, when deeper analysis may present a very different picture.
Hat-tip: thanks to David Weston for highlighting this research to me.
* Full source of research: Kalla, Joshua and Broockman, David E., The Minimal Persuasive Effects of Campaign Contact in General Elections: Evidence from 49 Field Experiments (September 25, 2017). Forthcoming, American Political Science Review; Stanford University Graduate School of Business Research Paper No. 17-65. Available at SSRN: https://ssrn.com/abstract=3042867.