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Effective Politics

An Analysis of Political Ad Efficacy

Every election cycle, Americans are inundated with political ads. Whether on legislation or candidates or scandals, these ads all intend to shape the public’s opinion and thus voter decisions.

In recent years, with the establishment and legalization of super PACs, there have been increasing concerns about the inequitable influence the rich have over the voting populace with their ability to skew votes by purchasing additional ad broadcasting time. Does the candidate with the most ads and the longest broadcasting time win?

Not necessarily, according to a study published in 2020, by Yale political scientist Alexander Coppock.

Contrary to expectation, the study found that political ads may not be effective in changing the general view of a candidate or increasing the number of votes they receive. The study analyzed the effects of 49 advertisements during the 2016 presidential race on a sample size of 34,000 subjects. The study took into account and controlled for different variables such as the tone of the ad, the sponsoring candidate and party, the party of the viewers, as well as when and where the ad aired. Across all these variables, the study found that the ads did not significantly shift votes or garner additional support among voters.

However, the findings of this study did come with some caveats. Rather than analyzing an entire advertising campaign, the study only analyzed separate ads, so the conclusive results fail to explicitly show the cumulative effect that all the ads of a campaign would have. Additionally, political ads were found to raise candidates' profiles—which is very useful as voters tend to vote for candidates that they recognize. Although candidate favorability shifted by only 0.05 points (a minute change on a 1-5 point scale), the change in favorability was still statistically significant considering the sample size. Furthermore, the candidate a viewer intended to vote for shifted (a statistically insignificant) 0.007%.

These findings indicate that the influence of advertising campaigns on voters was still present. As a result, these small changes could still conceivably influence the outcome of a close election. However, it seems clear that there is an inefficiency in the way that the people are reached. To consistently win campaigns and to build the support necessary to accomplish any tangible goals, it seems that different strategies must be implemented.


Works Cited

  1. Coppock, Alexander, et al. “The Small Effects of Political Advertising Are Small Regardless of Context, Message, Sender, or Receiver: Evidence from 59 Real-Time Randomized Experiments.” Science Advances, vol. 6, no. 36, 2020, doi:10.1126/sciadv.abc4046.

Last Fact Checked on May 28th, 2021.


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