This work examines the existence of heterogeneity in the impact of issues on vote
choice in the American electorate. I begin by explaining the reasons for studying heterogeneity
in issue weights from both a methodological and substantive perspective.
In Chapter 2 I examine the aggregate effect of heterogeneity in costs of information
on the measures of issue salience derived from spatial models of voting. I find some
evidence that individuals who are uncertain about candidate issue positions do bias
these estimates, but the resulting bias is slight in the aggregate. However, the results
of this chapter are suggestive, indicating that different voters may use issues differently
or not at all, depending on their costs of information. In order to examine this
possibility further, individual measures of issue salience must be developed. Chapter
3 explores the utility of using survey questions about issue salience as the solution to
this problem. Unfortunately, most of the survey questions currently employed do not
prove to be useful in determining issue salience in spatial models of voting. Thus,
Chapter 4 attempts to determine individual level issue salience indirectly, using a
method that employs rank-ordered data to estimate separate issue weights for each
individual on each issue. I find a clear relationship between issue salience and costs
of information, with those individuals who face higher costs of information being less
likely to place weight on any given issue or consider multiple issues when deciding
who to vote for. Although I am able to employ this technique to learn a great deal
about the relationship between issue salience and the costs of information, this technique
is not suited for most datasets. Therefore, in Chapter 5 I develop a model that
allows for heterogeneity in issue weights, but is more widely applicable to the kind
of data generally available for studying American elections. I again find evidence of
heterogeneity in the impact of issues on vote choice in the American electorate and
the role that costs of information play in determining issue salience. Finally, I conclude,
discussing my findings and the implications they have for the political process
in the United States
