Title: Internet Experiments in the 2005 BES
1Internet Experiments in the 2005 BES
- David Sanders
- Harold Clarke
- Marianne Stewart
- Paul Whiteley
2Preferences and Party Choice
- Two traditions
- Downs and spatial modellers Preferences are
exogenous - Campbell and the social psychologists
Preferences are endogenous, determined by a
variety of contextual and conditioning factors
3Preferences are Exogenous
- Voters maximise utility by selecting the party
that is closest to them in a left-right
ideological space. Voter is utility for party k
is given by  - Ui(k) (xi sk)2
- where xi is is preferred ideological position
and sk is is estimate of the position of party
k. - Note here that xi is assumed to be time invariant.
4Preferences are Endogenous
- What happens if measures of ideological position
cannot be anchored in what voters say at time t
because their self locations are not exogenous? - Suppose that xi are affected by the campaign
messages to which they are exposed - xit g0 g1xit-1 gkzkt
- where gk is a vector of effect parameters and zkt
is a vector of campaign variables. - Formal theory implications How do we obtain an
equilibrium in this situation? Can only do so if
we make further assumptions about zkt - Empirical implications we need to know what t is
and what the relationship is between xit and zkt
5How can this question be addressed?
- Experimental work an obvious approach do voters
shift their ideological positions if they are
given new information analogous to the
information they receive during campaigns? - Considerable advantages in conducting experiments
on representative national samples much more
likely to produce generalisable conclusions. - One way of assessing whether preferences differ
at two points in time is to give feedback to
respondents about their initial ideological
positions. - In conjunction with these initial positions
the xit-1 in our previous slides we can also
give campaign information the zkt in our
previous slides for example about the
positions of the parties - The internet represents an ideal vehicle for
providing feedback about the xi and for
manipulating the zkt
6Procedure the Internet Survey Experiments
- Ask respondent to self-locate on two 0-10 scales
tax/spend and liberal/authoritarian - Later in survey show respondent where s/he is
located in 2-d space defined by earlier responses - Ask if respondent wishes to re-locate self
- Split sample on cues provided (eight experimental
groups plus control see next slide) - Explore differences in patterns of response in
control and test groups
7What are the zkt?
- Two general sets of zkt
- Parties
- Leaders
- and combinations
- Experiments
- 1 Control just feed back xit-1 for Respondent
(R) - 2 R average voter
- 3 R party supporters for Lab, Con LD
- 4 R named leaders (Blair, Howard, Kennedy)
- 5 R leader party label
- 6 R parties 1983 scenario
- 7 R parties 1964 scenario
- 8 R parties 2005 scenario
- 9 R leaders supporters (5)
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9Note the difference between the control and all
test groups
1 Control 4 R leaders 7 R parties 1964
scenario 2 R average voter 5 R leader
party label 8 R parties 2005 scenario 3 R
party supporters 6 R parties 1983 scenario 9
R leaders supporters (5)
101 Control 4 R leaders 7 R parties 1964
scenario 2 R average voter 5 R leader
party label 8 R parties 2005 scenario 3 R
party supporters 6 R parties 1983 scenario 9
R leaders supporters (5)
Differences between control and each test group
almost all statistically significant
111 Control 4 R leaders 7 R parties 1964
scenario 2 R average voter 5 R leader
party label 8 R parties 2005 scenario 3 R
party supporters 6 R parties 1983 scenario 9
R leaders supporters (5)
Differences between control and each test group
almost all statistically significant
12Modelling absolute changes in self-locations
- With multivariate controls, it is the
party-based effects than continue to be
statistically significant respondents change
their tax-spend ideological positions in response
primarily to party cues. - Same result with crime-rights scale and with
Euclidean distance model based on the two scales
in a 2-d space.
13Modelling directional changes in self-locations
- Same pattern of effects observed with separate
models of cues relative to Rs Personal
Pre-experimental positioning of self and of the
parties. - Conclusion positive coefficients indicate that
PARTY CUES ATTRACT
14Conclusions
- Spatial model of voter utility assumes that
voters ideological/policy preferences are fixed.
- When people are invited to adjust their recently
made self-placements on two ideological scales, a
non-trivial proportion of them elects to do so. - Voters xit-1 values differ from their xit
values even within the space of a few minutes. - The type of positional cues to which people are
exposed the zij affects the extent to which
they wish to adjust their self-placements. - Information about the positions of named party
leaders seems to have little effect on
adjustment. - Information about parties, party supporters
or leaders with party labels does affect the
extent to which people wish to adjust.
15Conclusions.
- Analyses of respondents directional movement
suggests that voters are attracted to party cues
(of whatever sort), rather than repelled by them.
- Party cues help to persuade people to shift
their ideological/policy positions. - The internet allows relatively sophisticated
survey experiments to be conducted with
representative samples of the electorate, rather
than with small and unrepresentative groups of
(e.g.) undergraduate students. - Future experiments need to simplify the
stimuli, e.g. single or two-party stimuli
allowing respondents to vary parties positions
as well as their own.
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17Party-based comparisons with control tend to give
higher eta values than leader-based equivalents
18Again, party-based comparisons with control tend
to give higher eta values than leader-based
equivalents