Persuasion and political communication


Policy deliberation and persuasion

In a randomized experiment in cooperation with two national parties competing in the 2013 congressional election in the Philippines, we estimate the causal effect on voting behavior of a town-hall style campaign in which candidates discuss their campaign platform with small groups of citizens. Keeping the parties' platform fixed, we find that this "deliberative" style of campaigning has a positive effect on parties' vote shares compared to the status quo, in which voters play a passive role. Consistent with the parties' advocacy for underprivileged groups, we observe heterogeneous effects by income and gender. We show that the larger effect of town-hall meetings on women and poor voters arises because deliberative campaigns increase voters' attention to parties' platforms and change their attitudes on gender discrimination and poverty.

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The impact of news photos on support for war

What effect does the media have in generating support for war? Using two experiments embedded in online surveys, we examine the impact of news photos on support for military action. In 2011, respondents were asked about support for ongoing military involvement in Afghanistan while being randomly exposed to one of two photos—one of a soldier with a child, the other of a soldier with a gun. The former photo increased expressed support for war; and the effect was greater for those who self-identify as being very interested in international affairs. Three years later, a follow-up experiment was fielded that looked both at the past intervention in Afghanistan and ongoing interventions in Syria; results were very similar. Both experiments speak to the potentially profound role of mass media in generating support (or not) for foreign military engagements, and the increased impact of frames on those who are more attentive to the issue domain.

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Does the message or the messenger persuade?

In this study we were interested in the question of which elements of political communication are persuasive. We worked together with the "yes" side of the 2009 British Columbia referendum on electoral reform to implement a design in which we randomized three channels of political communication: the messenger, the message and endorsements. We find evidence for a strong campaign effect during the referendum. Both message-based and endorsement-based campaigns seemed to work but we find a surprisingly muted role for idiosyncratic features of messengers, i.e. political campaigners.
People: Torun Dewan; Macartan Humphreys

Funding: Columbia-LSE Research Fund


Testing the power of arguments

How can we determine which arguments in a referendum are most persuasive? We show that the Bradley–Terry model has several features that make it well-suited to this task, and thus preferable to other, more conventional approaches. Using a survey experiment conducted during an electoral reform referendum in Ontario, Canada in October 2007, we demonstrate how unstructured and structured Bradley–Terry models can be straightforwardly fitted and interpreted. In doing so, we gain insight into the factors that determine support for electoral reform. We identify a status quo bias and find that power varies with mention of fairness, local control over candidate selection, and the role of political parties. We conclude by discussing the limits, extensions and further applications of such models in electoral studies and political science more broadly.


Persuasion among party activists

Should party leadership candidates communicate their policy positions to the party convention delegates? And should they do so when their own ideal position is outside their party's mainstream? We examined these questions using a field experiment during the 2006 Liberal Party of Canada leadership race. We look at how the communication of controversial policy positions through direct mail affect delegates' perceptions of and support for the front running candidate. Working with the Michael Ignatieff campaign during the race, we randomly assigned a subset of convention delegates to receive a direct mail treatment featuring policy messages outside the mainstream of the party. Using a survey instrument, we measured the effects of this treatment on delegates' ratings and preference ordering of leadership candidates. The effects of the direct mail were principally negative; receiving the mail reduced the probability of the candidate being supported.
People: Peter Loewen