Persuasion and Spatial Theory

How Large and Long-lasting Are the Persuasive Effects of Televised Campaign
Ads? Results from a Randomized Field Experiment

Alan Gerber et al.
American Political Science Review, February 2011, Pages 135-150

Abstract: We report the results of the first large-scale experiment involving paid
political advertising. During the opening months of a 2006 gubernatorial campaign, approximately $2 million of television and radio advertising on behalf of the incumbent candidate was deployed experimentally. In each experimental media market, the launch date and volume of television advertising were randomly assigned. In order to gauge movement in public opinion, a tracking poll conducted brief telephone interviews with approximately 1,000 registered voters each day and a brief follow-up one month after the conclusion of the television campaign. Results indicate that televised ads have strong but short-lived effects on voting preferences. The ephemeral nature of these effects is more consistent with psychological models of priming than with models of on-line processing.
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A Spatial Theory of Media Slant and Voter Choice

J. Duggan & C. Martinelli
Review of Economic Studies, April 2011, Pages 640-666

Abstract: We develop a theory of media slant as a systematic filtering of political
news that reduces multidimensional politics to the one-dimensional space perceived by voters. Economic and political choices are interdependent in our theory: expected electoral results influence economic choices, and economic choices in turn influence voting behaviour. In a two-candidate election, we show that media favouring the front-runner will focus on issues unlikely to deliver a surprise, while media favoring the underdog will gamble for resurrection. We characterize the socially optimal slant and show that it coincides with the one favoured by the underdog under a variety of circumstances. Balanced media, giving each issue equal coverage, may be worse for voters than partisan media.

Nod to Kevin Lewis