W hether coefficients for “promote” ads should be positive and statistically significant is an open question.
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On the one hand, it may be that viewers extrapolate from such ads and conclude that government as a whole should
be seen in a brighter light. On the other hand, it may be that some viewers see all political ads as distasteful to
varying degrees, in which case weak, and possibly even negative, coefficients should be expected. Regardless of
results for these particular variables, though, the pattern across the five ad tone measures should be the same–most
importantly, the most strongly negative effects on respondents’ attitudes are expected for pure attack ads.
To accommodate the declining marginal effect of additional ads, we took the natural log of this count.
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The Impact of Ad Exposure on Citizens’ Political Attitudes
Initial models make use of the Wisconsin Advertising Project’s five-category
classification of ad content. All dependent variables are coded such that larger values reflect
more positive assessments. If negative ads adversely affect citizens’ political judgments, then
signs of this may take several forms. The first and most straightforward expectation is that large
and statistically significant negative coefficients will be produced for exposure to pure attack
ads. That is, as a survey respondent’s level of exposure to unequivocally attack-oriented ads
rises, we should see a decline in evaluations of Congress and in perceptions of political efficacy.
Second, similar results should be obtained for those contrast ads that include a preponderance of
attack material. Third, because the five categories in the WiscAds ad tone typology are ordered,
a consistent pattern of effects should be found across the five indicators, with the highest values
emerging for commercials that exclusively promote a candidate, and the lowest values for pure
attack ads.
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Results for the initial set of models are reported in Table 1. Control variables in all
models include political knowledge, ideology, partisanship, education, sex, age, and two
measures of the intensity of the campaign context–a dummy variable for whether the
respondent’s U.S. House district had a competitive and/or open seat contest in 2002, and a count
of the total number of political ads aired in the respondent’s media market. The four models
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concerning judgments about Congress also include as controls a measure of presidential
Convention