UC San Diego

Congressional candidates spend the majority of their campaign funds on television advertising to reach the highest number of voters, spending almost $300 million in 2014 alone. Yet previous research has not fully answered if advertising is associated with increased electoral success. In particular, this represents the first analysis of television advertising in elections for the United States House of Representatives. It also represents the first analysis of competitive, low information elections where voters have limited knowledge of the candidates. First, I examine U.S. House races over six electoral cycles from 2000-2012 to test how positive, negative, or contrast ads correlate with electoral success. Then, I build upon this analysis with a novel experiment that more closely models the information environment in competitive, low information campaigns by exposing respondents to one advertisement from each candidate using past television advertisements. This provides causal evidence linking the tone of an advertisement with changes in electoral support. Finally, since the 2010 Citizens United ruling interest groups are spending increasingly large amounts of money in U.S. congressional elections. Instead of advertising tone, I test whether the advertising sponsor influences how voters perceive and evaluate the candidates, comparing traditional candidate-sponsored ads with interest group-sponsored ads. The results highlight how tone and sponsor yields little effect on electoral support. The effect that does exist is not the intended effect of an ad, but rather the backlash against the candidate sponsoring a negative ad. However, candidates can avoid this issue by having interest groups air their negative ads on their behalf. I find that interest group ads are equally persuasive compared to candidate-sponsored ads and yield a smaller backlash penalty against the preferred candidate. Taken together, these findings have important consequences for the role of advertising in U.S. elections and the power interest groups are increasingly wielding to influence electoral outcomes.