Political Science 17.20
Introduction to American Politics
Professor Devin Caughey
MIT Department of Political Science
Public Opinion
Lecture 13 (March 21, 2013)
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Outline
1
From Individual to Aggregate Opinion
2
The Rational Public?
3
Elites, the Media, and Partisans
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Outline
1
From Individual to Aggregate Opinion
2
The Rational Public?
3
Elites, the Media, and Partisans
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The Incoherence of Individual Attitudes
Attitude: psychological tendency expressed by evaluating
an entity with some degree of favor or disfavor
The attitudes of individual citizens tend to be:
Ignorant
Unstable
Ideologically inconsistent
More informed/engaged citizens are more ideological, but
this reflects emotional factors as much as cognitive ones.
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How Do Citizens Respond to Survey Questions?
RAS Model: Attitudes are constructed “on the spot” on the
basis of a sample of considerations derived from
information received via the mass media.
On-line Processing: Attitudes towards some high-profile
objects (e.g., president) may reflect more information than
citizens can remember.
→ Save the summary evaluation but forget the details.
Heuristics: Gut feelings are an example of a cognitively
efficient (though fallible) decision shortcut.
→ Is it unreasonable to vote for Obama “because he’s black”?
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Outline
1
From Individual to Aggregate Opinion
2
The Rational Public?
3
Elites, the Media, and Partisans
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Emergent Properties of Public Opinion
The Miracle of Aggregation:
Random noise in citizens’ responses (measurement error)
cancels out when they are added together, strengthening
the underlying signal.
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Parallel Publics
Education: Legal abortion if woman wants no more
children, 1972-1990
100
90
% Allow legal abortions
if woman wants no more children
80
70
60
50
40
30
20
10
0
1972
1974
1976
1978
1980
1982
1984
1986
1988
College graduate
High school grad
Some college
Not high school graduate
1990
Image by MIT OpenCourseWare.
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Outline
1
From Individual to Aggregate Opinion
2
The Rational Public?
3
Elites, the Media, and Partisans
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Zaller’s Theory
Three main factors:
1
Predispositions (party, values)
2
Political awareness (attention, knowledge)
3
Information flows (elite → media → public)
Mainstream effect:
Elites agree =⇒ support increases with political information
Polarization effect:
Elites disagree =⇒ opinion polarizes as information increases
→ If messages imbalanced, relationship may be curvilinear.
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Support for the Vietnam War
Mainstream
Percent support for war
1964
100
→
1966
Hawks
Hawks
Doves
Doves
Polarized
1970
Hawks
75
50
25
0
Political awareness
Political awareness
Doves
Political awareness
Image by MIT OpenCourseWare.
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Berinsky’s Revision
Berinsky criticizes the claim that citizens make rational
decisions about war based on the anticipated costs.
The pattern of elite conflict is crucial.
But citizens are not just passive recipients of elite
messages, but rather can infer the “correct” position for
them based on the source (i.e., Bush) of pro-war
messages, even in the absence of countervailing
messages.
Is this a reasonable heuristic?
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The Iraq War
Iraq War Worth Fighting
Probability of supporting
war
1
0.5
0
0
0.5
1
Information
Strong Republican
Strong Democrat
Image by MIT OpenCourseWare.
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17.20 Introduction to American Politics
Spring 2013
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