Candidates for public office regularly make vague statements that leave voters uncertain about the policies they intend to pursue. Why do candidates employ ambiguity, and what are the consequences? Two factors have impeded empirical research on these fundamental questions. First, existing datasets do not measure the ambiguity in candidate statements and distinguish it from other sources of uncertainty. Second, previous research had difficulty distinguishing causes from effects; the perceived and actual ambiguity of candidates may depend on, as well as influence, the preferences of voters.

The Principal Investigators will puruse a two-pronged investigation of the relationship between candidate ambiguity and voter choice. First, they will run survey experiments that manipulate the ambiguity of candidate platforms. In their experiments, a nationally representative sample of U.S. adults will chose between candidates who state policy positions with varying levels of ambiguity. The experiments will reveal whether, and under what conditions, candidates can gain or lose support by taking ambiguous positions.

In the second prong of the study, the Principal Investigators will study the actual uses of ambiguity in U.S. elections by analyzing the transcripts of all presidential debates since 1960. The data will shed new light on many questions: Do candidates avoid or limit their ambiguity in circumstances when our experiments suggest that ambiguity would be harmful? Do candidates use ambiguity differently in primaries than in general elections? Do candidates employ strategies of ambiguity more often on complex issues, or on issues owned by their party or gender? And do candidates call attention to ambiguity when our experiments show that it could be advantageous?

In addition to advancing our understanding of politics, the project will have several broader impacts. It will actively involve undergraduate and graduate students in scholarly research; develop new experimental methods that could be used to study other features of campaigns; and provide practical lessons for candidates, advisors, and citizens who are involved in political campaigns.

National Science Foundation (NSF)
Division of Social and Economic Sciences (SES)
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Brian D. Humes
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Stanford University
Palo Alto
United States
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