Assessing accountability in a post-citizens united era: The effects of attack ad sponsorship by unknown independent groups
According to this article the power of ads sponsored by independent groups rests not just in their sheer volume, but also in their relative effectiveness. When an attack ad is sponsored by an independent group, the authors found that the ad is far more effective than when the same ad is sponsored by a candidate.
They conducted an experiment by showing a negative state-level election ad about a particular fictitious candidate. The ad was either endorsed by the candidate’s opponent, by a nonpartisan independent group, or unattributed to either and shown to a sample of 1,500 U.S. adults. Regardless of sponsorship, researchers found that the ads were similarly persuasive regarding the flaws of the candidate who was the target of the ad. They suggest that since there is reduced potential of backlash from voters, independent groups may face incentives to produce highly controversial advertisements while facing relatively few incentives to be truthful in ads.