Social Network and Voting Behavior in
reference to a differential effect of a multiparty versus a two-party system:
With a Comparison between Japan and
US Election data
ELECTORAL SYSTEMS AND ELECTORAL
POLITICS: Bangalore CSES Workshop &
Planning Committee Meeting
2- 4 November 2006
Ken’ichi Ikeda
The University of Tokyo
Abstract
 In a comparative analysis of American and Japanese voting behavior, the
effects of social networks on voting behavior and the expression of
political opinion were investigated.
 Using an Interpersonal Political Environment (IPE) approach, which
assumes that social networks form influential environments with respect to
such behavior, a consistent pattern of influence via social networks was
detected in both countries.
 A similar pattern is also observed with respect to voluntary expressions of
opinion about politicians.
: Further analyses on Japanese data assures that this IPE effect reflects
voluntary judgment of voters.
 Then, the effect of social networks seems to be caused by the acceptance
of viewpoint of others within IPE as a political reality (which helps
voluntary decision to vote).
: Effect was larger in the US than in Japan
 The difference is partly attributable to institutional difference between the
US and Japan, specifically the political party configuration
Interpersonal influence in U.S.
Findings of interpersonal influence on
voting patterns have been well established
in the US (Lazarsfeld et al., 1948)
The influence is more systematically
investigated in recent studies using ‘social
network batteries’ to measure daily
interpersonal political communication
(Huckfeldt & Sprague, 1995).
Japanese Voting “Peculiarity”
 Japan is often described as having collectivistic culture, which means
interpersonal influence is substantial.
 In this sense, the same pattern of interpersonal influence as in US could be
observed. However, the meaning of influence might have been different.
 Previous studies of Japanese elections ;
Voters are often described as passively mobilized to vote in traditional
contexts
 Richardson (1991) points out that in Japanese elections in the 1970s,
“people’s voting support is sought via mobilization of social networks
and group affiliations by “influence communications”.
“[These] communications are interpersonal and organizational
communications, designed to directly mobilize and manipulate voting
support through activation of personal obligations, feelings of deference,
or other kinds of sentiment pertaining to specific ongoing social
relationships that extend well beyond any given election campaign” (p.
339).
Often attributed to factors that are peculiar to Japanese collectivistic
culture. Is it true?
Generalization and more
 Exploration of the mechanism of any similarities and
differences is needed.
 Because,
 Decline of collectivism in Japan
 Japanese are no more collectivistic than Americans (Oyserman et
al., 2002; Matsumoto, 1999)
 Huge structural changes in Japan
 From multi-member single nontransferable vote system to mixed but
basically SMD system
 Beyond peculiarity contention, the micro-interpersonal
structural effect on both Japanese and American voting
behavior could be similar.
 In this context, I will analyze the interpersonal effects in
Japan and US.
The IPE effect as a hypothesis of
network effect
 An individual is embedded
in a network, which is
composed of others who
are connected to the given
individual through ties.
E
D
F
 We refer to this network as
the IPE (Interpersonal
Political Environment).
A
C
B
G
Figure 1. IPE for A
The IPE effect as a
hypothesis of network effect
 Others in the network are individuals who not only surround A, but
also form an environment that contributes to A’s social and political
reality. Although others in the network form a collection of individuals,
their product—that of the IPE they represent—is a collective entity.
 In an IPE in which A’s political discussants are all LDP supporters,
there will be an information configuration that filters out most
unfavorable information about the LDP. In this situation, the IPE
promotes an LDP-favorable social reality for A. This effect is not
caused by any one individual, for instance opinion leader, but is a
collective result of A’s IPE.
The IPE effect as a
hypothesis of network effect
 This approach emphasizes the fact that others in the network
are agents of a variety of information resources to A, and play
an important part in constructing A’s social reality.
 IPE is more than an agent of information resources. Our
social reality is a joint product of individual belief, collective
support by others, and mass media information (Ikeda 1993,
1997), i.e. IPE is an essential part of our social reality.
 In this sense, people maintain their sense of reality
collectively in their personal environment, including their
voting behavior.
 Hypothesis 1: IPE effect
In both the US and Japan, the higher the ratio of IPE of a
specific Party X, the higher the probability that the respondent
will vote for Party X.
Effect of social network;
Spontaneity (1)
 However, supposing “collective influence” of IPE does not
mean that people are influenced by conformity pressure.
 The phenomenon which has not been well investigated but
important focus in the context of interpersonal effect, i.e.
spontaneity dimension: passiveness vs. activeness.
 Passiveness : The effect of network derives from a passive and conforming
power mechanism.
 Activeness : Spontaneous influence acceptance by an informational or
referent power mechanism.
 The latter was only emphasized by Putnam.
 Passive influence such as coercive power which makes people
conform should be more focused on.
 In classical studies (Asch, 1951; Deutsch & Gerard, 1955),
group influence has often been thought of as a result of passive
and conforming pressure (even in the US context).
 Is it still true in the contemporary world?
Effect of social network;
Spontaneity (2)
 Passive vs. spontaneous distinction is especially
consequential for actual democratic practices
 The conformity pressure could be a factor for the formation
of the “dark side of social capital”
 It may restricts members of a given group to commit a
specific behavior or subscribe to a specific political
orientation, thus disturbing open discussion and making the
members intolerant to non-conforming deviants.
 If the mechanism is spontaneous (informational or
referent), the same concurrent seeking is interpreted quite
differently
 Trust on others is essential here and it goes together with
positive social capital
 Open discussion, and tolerance to heterogeneous ideas
due to the lack of coercive power.
Effect of social network;
Spontaneity (3)
 As was shown, historically in Japanese society, social
networks played negative roles in modernizing Japanese
political attitude and behavior (Abe, Shindo & Kawato, 1990;
Richardson, 1991).
 This claim presupposes that the group influence mechanism
under Japanese society is by conformity enforcement, i.e.
non-spontaneous power is the major engines, especially to
mobilize people to vote some specific candidate.
 There seems to be a good reason, however, that this is not
the case anymore due to the huge structural changes of the
society in 1990 and after (as mentioned before).
 Let’s empirically check this point.
Hypotheses and strategies on
analyses (1)
Hypo 2)
Spontaneous effect hypothesis
 2A) Spontaneous expression on
PM Koizumi or Bush/Gore
調査票番号
 Positive and negative open-ended
responses on politicians; these are
based on spontaneous cognitive
process.
 If these spontaneous expressions
are a positive function of the IPE's
political color, IPE’s effect is not
from conformity.
Conformity pressure functions are
only limited to the very situation under
specific and concrete group pressure
(voting situation).
0000000
0000001
0000002
0000003
0000004
0000006
入力欄
入力欄
Positive on
PM
Negative on
PM
わかりやすくしゃ
べってるし、やら
なければならな
いこともやって
る。
はぎれがいいと
いうか、言うこと
が明確
今のところあま
り枠に縛られて
いない。内政に
関しては、いい
ところまではいく
と思う。
改革すると言っ
切っている点
なんかパワーが
ある。やる気が
見られる。
新しく構造改革
ということで経済
が良くなればい
いと思う。
小泉内閣はいい
けど、自民党の
中が変わってな
いところ。
実行力はわから
ない。
世界の中の日
本という立場で
は、今の接し方
では危ういと思
う。
今のところ何も
変わっていない
し、足並みがあ
まりに揃ってい
Hypotheses and strategies on
analyses (2)
Hypo 2) Spontaneous effect hypothesis
2B) Spontaneity of political participation (JP only)
 When conformity pressure is working: facilitates Ego’s campaign
participation in accordance with the IPE’s political color, while oppressing
participation in discordance with that political color
 Conformity pressure is a force that coerces human behavior in a specific
direction which at the same time oppresses behavior going to the opposite
direction.
 When spontaneous power is working; IPE facilitates political participation
consistent with, but without suppressing opposing directions (i.e. tolerant).
IPE is only providing information or a behavioral referent, which is
adopted/chosen by ego spontaneously (This is not testable in voting
behavior because of its trade-off nature).
2C) Controlling mobilization variable (JP only)
 Mobilization attempts often utilize traditional power of social network, i.e.
conformity (as was old Japanese voting theories).
 If mobilization is predictive of vote and at the same time reduce the effect
of IPE, spontaneity hypothesis will be in danger.
Before testing Hypos: How we measure IPE?
 social network battery with using “name generators”
 Components of network: Japan-US
%
Number of others in the network
Survey
CNEP93
Country/Year
Japan/93
JESII
Japan/95
JESII JEDS2000
JESIII
JESIII
Japan/96 Japan/2000 Japan/2001 Japan/2001
Spouse +
Political
Significant Significant Significant
frequent Political discussant +
Definition of other
other*
other
other contact other discussant
spouse
0
34
28
33
7
30
11
1
35
27
26
20
28
41
2
17
20
20
9
20
23
3
8
25
21
64
11
14
4
5
11
12
5
2
Average number of other
1.2
1.4
1.3.
2.3
1.4
1.7
N
1333
2076
2299
1618
2061
2061
* The last one is a political discussant
CNEP92
U.S.
NES2000
U.S.
Significant Political
other* discussant
9
26
18
19
15
20
19
14
18
21
22
2.8
1.9
1318
1551
JP has less network members if it is significant others/ political
discussants
Relationship with net-other
%
Number of others in the network
Survey
CNEP93
JESII
JESII JEDS2000
JESIII
JESIII
Country/Year
Japan/93
Japan/95 Japan/96 Japan/2000 Japan/2001 Japan/2001
Relationship with other
Spouse
31
34
33
34
28
40
Another immediate family member
13
13
13
7
14
11
A relative
4
4
5
10
5
4
A friend
24
24
18
35
18
15
A coworker
16
16
19
14
20
17
A neighbor
3
3
6
5
4
The same church
The same leisure activity group
2
2
4
6
5
The same organization of
group (the other group)
4
2
6
5
4
Other
1
1
2
1
0
Network N**
1620
2934
2969
3718
2946
3567
** Number of paired data (Respondent and partner)
CNEP92
U.S.
NES2000
U.S.
17
33
37
17
10
9
-
14
29
27
15
8
-
-
6
2890
3752
JP’s predominance of spouse and small number of neighbors
Talk and guess on political matters
Table１b Differences of others in the network by types of network battery (2)
Survey
Country/Year
CNEP93
Japan/93
JESII
Japan/95
JESII
Japan/96
Significant
Significant
Definition of other
other*
other
Amount of political discussion with other
Max***
15
8
34
37
32
42
Min
16
12
DK.NA.
3
2
Network N
1620
2934
*** Expression on max/min differs from survey to survey
Guess of political orientation of other
Party voted
LDP
24
JSP/SDP
7
CGP
5
NFP
DPJ
JCP
2
New party
8
Other party
2
Don't vote
2
Independent
DK.NA
51
Network N
1620
JEDS2000
JESIII
Japan/2000 Japan/2001
Spouse +
Significant
frequent
Political
other contact other
discussant
6
31
46
16
2
2969
Party voted
20
7
17
3
2
6
46
-
Party voted
24
2
13
5
3
2
4
48
-
2934
2969
JESIII
Japan/2001
Political
discussant +
spouse
CNEP92
U.S.
％表示
NES2000
U.S.
Significant
other*
Political
discussant
20
50
25
5
0
3752
24
53
22
1
0
2890
4
30
61
5
3718
21
60
17
2
2946
17
54
26
3
3567
21
1
2
2
1
0
24
48
-
Party voted
31
2
6
4
2
1
54
-
Party voted
31
2
6
4
2
1
55
-
3718
2946
3567
PID
Party voted
Party voted
40
38 Democrat
35
42 Republican
14
3 Third party
1
2
9 Don't vote
9
8 DK.NA
1 Net-other was
under voting
3752
2890
talk (less) and less guess on politics in JP
The test of hypotheses
National sampling surveys with network batteries in both
Japan and the US, particularly Japanese JES3 and US
NES2000 data.
Data source:
JES3= 2001-2005 panel survey with 9 waves
mainly focus on 2001 election with additional analyses
on 2003 and after elections
NES2000= pre-post survey on the Presidential Election
2000
JESIII
2001 House of Councilors Election
[Pre FtF Survey]
Target period: 19 July to 28 July, 2001 (29 July was the Election
day
Sample:
3,000 Japanese voters (over 20 years old)
based on 2 stage stratified sampling
Response rate: 2,061(68.7%)
[Post Telephone survey]
Target period: 1 August to 5 August, 2001
Sample:
panel from the previous wave.
Response rate: 1,253 (41.8% against the original sample; 60.8%
against the 1st wave respondents; 791.% against those who
provided their phone numbers)
JESIII
2003 House of Representatives Election
［Pre FtF survey］
Period: 29 October to 8 November (9 Nov was the election day)
Respondents
Total
Sample=3759, Response= 2162, Resp rate= 57.5%
Panel
2334
1340
57.4%
New Recruit
1425
822
57.7%
(addition of sample by random sampling)
［Post Ftf survey]
Period: 13 November to 24 November
Respondents
Total
Sample=3573 Response= 2268, Resp rate= 63.5%
Panel
2356
1828
77.6%
New Recruit
1217
440
36.2%
Those who were accessible in both of the pre and post survey= 1769
Testing Hypothesis 1
(IPE effect on voting behavior)
 In the Japanese 2001 House of Councilors election, voters had two
tickets
 Ordered logit analysis
 In the US Presidential Elections: Gore =0 and Bush =1
 Logit analysis
Japan
Dependent
Independent
vars. variable
Gender
Age
Education
City size
Knowledge
LDP support
DPJ support
LDP support ratio by political
discussants
DPJ support ratio by political
discussants
U.S.
variable
IndependentDependent
vars.
Gender
Age
Education
Knowledge
Party Identification: Demo-Rep
Democart support ratio by political
discussants
Republican support ratio by
political discussants
IPE effects are estimated
by controlling
demographic vars, and
party ID (source of bias).
By controlling party ID,
we can reduce
“projection” effect
statistically.
The result of the test on
Hypothesis 1
 Even by controlling for party ID variables, the results show a
significant net effect of perceived votes.
Table 2 Effect of net-other on vote
Japan: 2001 House of Councilors
Dependent variable
Number of
LDP vote
Coef.
0.18
0.01 *
-0.08
0.01
0.00
0.83 ***
-0.06
Number of
DPJ vote
Coef.
-0.17
0.02 *
0.03
0.07
0.04
-0.34 **
0.92 ***
Gender
Age
Education
City size
Knowledge
LDP support
DPJ support
LDP support ratio by political
discussants
0.78 ***
-0.66 *
DPJ support ratio by political
discussants
-1.15 ***
1.68 ***
Cut point 1
1.98 2.66 Cut point 2
3.10
3.91
N
1011
1011
LR
331.23
232.13
P-value
0.00
0.00
Quasi R-square
0.16
0.18
P-value .05<p=<.1 +, .01<p=<.05 *, .001<p=<.01 **, p=<.001 ***
US: 2000 Presidential vote
Dependent variable
Gender
Age
Education
Knowledge
Party Identification: Demo-Rep
Democart support ratio by political
discussants
Republican support ratio by
political discussants
constant
N
LR
P-value
Quasi R-square
0=Gore
1=Bush
Coef.
-0.20
0.00
-0.07
-0.10
1.13 ***
-0.97 *
2.21 ***
-2.47 *
891
787.94
0.00
0.64
The result of the test on
Hypothesis 1
 The IPE effect hypothesis was supported in Japan
 The IPE effect in the US showed the same pattern as in Japan.
Figure 2 Post hoc simulation of IPE effect
Probability of vote for
LDP or DPJ
Probability of vote for Bush
2 vote
1 vote
0 vote
1
1
0.8
0.8
0.6
0.6
0.4
0.4
0.2
0.2
IPE
0
0
0
0
J 1
P 1
LDDPJ
PJ r DPLDP
DP
r
D
L
fo d
fo d
d
nd
an
te 0 an
te 0 an
o
o
1
1a
v P
v
f
f
J
J
P
LD lity o DP
DP
y o LD
ilit
i
b
b
a
a
ob
ob
Pr
Pr
ＩＰＥ
m
De
d
an an
0
5
p
Re ep .2
R
1
em
D
d
R
Tie
. 25 m 0
m
De
e
D
d
n
d
an
1a
5
p
.7
Re
ep
.75
Further data on Japan
 The IPE effect hypothesis (Hypothesis 1) was supported
 People vote consistently with the net-others’ perceived votes.
Table 1 IPE effect on votes
year 2001
Dependent variables
LDP vote
DPJ vote
coef.
coeff.
Gender
0.28 *
-0.18
Age
0.01 +
0.02 *
Education
-0.05
0.03
Years of residence
0.17 *
-0.03
Megalopolis vs. Small Town
0.01
0.06
Knowledge
0.00
0.06 *
LDP support
0.83 ***
-0.37 **
DPJ support
-0.08
0.96 ***
LDP-IPE ratio
0.86 ***
-0.59 *
DPJ-IPE ratio
-1.08 *
1.73 ***
cutpoint 1
2.73 ***
2.71 ***
cutpoint 2
3.89 ***
3.99 ***
1164
1164
N
0.17
0.19
Pseudo R2
p value .05<p=<.1 +, .01<p=<.05 *, .001<p=<.01 **, p<.001 ***
year 2003
LDP vote
coef.
0.18
0.01 +
-0.02
0.17 **
0.06 *
-0.01
0.75 ***
-0.63 ***
1.02 ***
-2.13 ***
2.12 ***
3.63 ***
1510
0.25
Year 2004
DPJ vote
coeff.
-0.33 *
-0.01 *
0.05
-0.04
-0.04
0.03
-0.24 **
1.02 ***
-0.52 **
1.95 ***
-0.73
0.44
1510
0.20
LDP vote
coef.
-0.09
0.01
-0.04
0.23 ***
0.07 *
-0.13 +
0.92 ***
-0.81 ***
1.06 ***
-0.86 *
2.41 ***
3.58 ***
1512
0.28
year 2005
DPJ vote
coeff.
-0.05
0.00
0.13 *
-0.07
0.03
0.07
-0.20 **
1.13 ***
-0.31
1.47 ***
0.51
1.54 **
1512
0.19
LDP vote
coef.
-0.22
-0.01
0.03
0.09
0.02
-0.03 +
0.88 ***
-0.30 **
1.37 ***
-1.04 ***
0.32
1.81 **
1230
0.26
DPJ vote
coeff.
0.24 +
0.00
0.01
-0.10
0.00
-0.01
-0.21 **
0.91 ***
-1.18 ***
1.56 ***
0.35
1.42 *
1230
0.24
Testing Hypothesis 2A
(the spontaneity effect of discussants)
 Dependent Variables;
 Japan: Open-ended evaluations on the Koizumi cabinet.
We counted the number of positive and negative responses.
 88% of the voters gave one or more positive answers
36% did so on negative comment
 More than 30% gave two or more positive answers,
while 6% gave two or more negative answers.
 US ; Four open-ended answers
Positive and negative statements about the candidates Gore
and Bush.
More numerous than in the Japanese survey,
Around 30% gave two or more answers.
The result testing for Hypothesis 2A
Table 3 Effect of IPE on the political opinion expression
Japan: open-ended expressions on the Koizumi Cabinet
No of positive
Dependent variables responses
Coef.
Gender
0.39 ***
Age
0.00
Education
-0.12 +
City size
-0.03
Knowledge
0.07 ***
LDP support
0.10 +
DPJ support
0.08
Cabinet support
0.47 ***
ratio by political
discussants
cut point 1
cut point 2
cut point 3
-1.53
1.43
3.26
US: open-ended expressions on the Presidential Candidates
No of
negative
responses
Coef.
-0.29 *
0.00
0.25 ***
-0.06 *
0.06 ***
-0.28 ***
0.04
-0.42 ***
0.24
2.64
N
1332
1362
LR
47.97
117.87
P-value
0
0.00
Quasi R-square
0.0165
0.05
ｐ value .05<p=<.1 +, .01<p=<.05 *, .001<p=<.01 **, p=<.001 ***
Dependent variables
Gender
Age
Education
Knowledge
Party Identification: DemoRep
Democart support ratio by
political discussants
Republican support ratio by
political discussants
cut point 1
cut point 2
cut point 3
cut point 4
cut point 5
N
LR
P-value
Quasi R-square
No of
positive
responses
on Gore
Coef.
0.19
0.01 +
0.10 **
0.21 ***
-0.46 ***
0.68 ***
-0.68 **
0.79
1.73
2.59
3.45
4.21
1115
467.51
0
0.1367
No of
negative
responses
on Gore
-0.26 *
-0.01 +
0.10 **
0.27 ***
0.40 ***
0.11
0.86 ***
2.31
3.35
4.35
5.36
6.25
1116
410.75
0
0.1215
No of
positive
responses
on Bush
-0.01
0.01
0.04
0.12 **
0.55 ***
-0.16
0.85 ***
2.86
3.84
4.84
5.65
6.40
1115
515.08
0
0.1573
No of
negative
responses
on Bush
-0.23 +
0.00
0.18 ***
0.21 ***
-0.42 ***
0.51 **
-0.44 *
0.99
1.97
2.86
3.74
4.48
1114
390.89
0
0.1155
The result testing for Hypothesis 2A
 Japan: Without discussants’
support, two or more positive
comments were made by only
25% of the voters, whereas with
full discussants’ support, the
number rose by 10%. The reverse
was true for negative comments;
42% and 33% respectively,
resulting in a difference of nine
percentage points. In total, there
was a difference of 19 percentage
points between the effect in the
positive and negative responses.
Figure 3 Posthoc simulation of open-ended
responses on Prime Minister Koizumi
100%
80%
60%
2 or more
1
0
40%
20%
0%
Min・Positive
Max・Positive
Min・Negative
Max・Negative
Ratio of net-others Cabinet support
The result testing for Hypothesis 2A
Figure 4 Posthoc simulation of open-ended responses on Presidential Candidates
Positive Gore comments
Positive Bush comments
100%
100%
80%
80%
20%
ro
ng
St
St
100%
100%
80%
80%
Re
pu
bli
ca
n
ro
ng
In
de
pe
nd
en
t
0%
oc
ra
t
Re
pu
bli
ca
n
20%
St
St
ro
ng
In
de
pe
nd
en
t
oc
ra
t
0%
40%
De
m
20%
60%
ro
ng
40%
five
four
three
two
one
no response
St
60%
De
m
five
four
three
two
one
no response
Negative Bush comments
Negative Gore comments
ro
ng
Re
pu
bli
ca
n
0%
In
de
pe
nd
en
t
Re
pu
bli
ca
n
St
St
ro
ng
In
de
pe
nd
en
t
ro
ng
De
m
oc
ra
t
0%
40%
oc
ra
t
20%
60%
De
m
40%
five
four
three
two
one
no response
ro
ng
60%
St
 If discussants were
100% Democrat, the
probability of zeropositive comment for
Gore was only 17%,
but if discussants were
0% Democrat, the
probability was 71.
 The corresponding
probability for Bush
was 25% versus 76%.
Both of the cases had
more than 50
percentage point
differences.
five
four
three
two
one
no response
Further data on Koizumi
 Even after controlling verbal fluency (knowledge) and
political bias (party support), IPE effect survived consistently.
 Support Hypothesis 2A(2001-2005).
Table 7 IEP effect on spontaneous expression on the Cabinet
year 2001
year 2003
Year 2004
year 2005
N of positive
N of negative
N of positive
N of negative
N of positive
N of negative
N of positive
N of negative
Dependent variables expression
expression
expression
expression
expression
expression
expression
expression
coef.
coeff.
coef.
coeff.
coef.
coeff.
coef.
coeff.
Gender
0.46 ***
-0.19
0.14
-0.11
0.23 *
-0.12
-0.19
0.22 +
Age
0.00
0.01
0.01
0.01 *
0.00
0.00
0.00
0.01 **
Education
-0.13 *
0.29 ***
0.17 *
0.16 *
0.08
0.26 ***
0.22 **
0.38 ***
Years of residence
-0.03
-0.08 +
-0.08
-0.11
0.01
0.02
0.07
0.06
Megalopolis vs. Small Town
-0.01
-0.04
-0.01
-0.04
0.00
0.03
-0.03
-0.05 +
Knowledge
0.08 ***
0.06 **
0.04 *
0.09 ***
0.14 *
0.26 ***
-0.01
0.07 ***
LDP support
0.18 ***
-0.25 ***
0.30 ***
-0.01
0.40 ***
-0.17 **
0.27 ***
-0.12 +
DPJ support
0.16 *
0.05
0.08
0.34 **
-0.08
0.21 **
0.08
0.24 **
Cabinet support IPE ratio
0.47 ***
-0.40 **
0.91 ***
-0.58 ***
1.24 ***
-0.83 ***
1.20 ***
-0.58 ***
cutpoint 1
-1.22 **
0.51
0.98 +
-0.14
0.65
-0.18
0.48
1.21 *
cutpoint 2
1.70 ***
2.91 ***
3.40 ***
2.52 ***
3.01 ***
2.30 ***
3.21 ***
3.80 ***
cutpoint 3
3.45 ***
4.93 ***
5.15 ***
4.15 ***
5.10 ***
4.20 ***
5.05 ***
5.58 ***
1534
1570
1321
1321
1399
1399
1250
1250
N
0.02
0.05
0.04
0.05
0.07
0.05
0.06
0.05
Pseudo R2
p value .05<p=<.1 +, .01<p=<.05 *, .001<p=<.01 **, p<.001 ***
Campaign participation as dependent
variable; spontaneity effect (H2B)
 Campaign-related participation activities as dependent variables.
 The stronger LDP-IPE, the more voters are inclined to join LDP
campaign related activities. The reverse effects do not appear, i.e.
DPJ-IPE does not decelerate participation for LDP.
 The same is true for DPJ-IPE.
 H 2b was supported strongly in this test.
Table 4 IPE Effect on campaign participation
year 2001
participation
participation
Dependent variables
for LDP
for DPJ
coef.
coeff.
Gender
-0.69 **
-0.99 **
Age
0.02 +
0.01
Education
0.21
-0.25
Years of residence
0.03
-0.02
Megalopolis vs. Small Town
0.01
0.03
Knowledge
0.05
0.05
LDP support
0.42 **
-0.33 *
DPJ support
-0.07
0.45 *
LDP-IPE ratio
0.86 ***
-0.28
DPJ-IPE ratio
0.59
1.31 *
-4.11 ***
-1.92
constant
1164
1164
N
0.11
0.12
Pseudo R2
p value .05<p=<.1 +, .01<p=<.05 *, .001<p=<.01 **, p<.001 ***
year 2003
participation
participation
for LDP
for DPJ
coef.
coeff.
-0.28
-0.58 *
-0.01
-0.01
-0.04
0.00
0.39 **
0.17
0.11 +
-0.06
0.04
0.07 *
0.77 ***
0.01
-0.14
0.66 ***
1.65 ***
0.23
0.26
2.04 ***
-6.70 ***
-3.18 **
1622
1622
0.22
0.20
Year 2004
participation
participation
for LDP
for DPJ
coef.
coeff.
-0.48 +
-0.08
0.00
0.00
0.09
0.19
0.19
0.24
0.09
0.03
0.05
0.33 *
0.74 **
0.11
-0.04
0.84 ***
1.85 ***
0.47
0.50
2.13 ***
-6.25 ***
-6.56 ***
1721
1721
0.22
0.22
year 2005
participation
participation
for LDP
for DPJ
coef.
coeff.
-0.18
-0.58 +
0.01
-0.01
0.12
0.02
0.00
0.21
0.09
0.17 *
0.05
0.02
0.86 ***
0.39
0.45 +
1.23 ***
1.36 ***
-0.63
-0.19
0.78 *
-6.28 ***
-5.44 ***
1300
1300
0.18
0.23
Campaign participation as dependent
variable (H2B)
 Do these spontaneous effects survive even after
controlling mobilization variables?
 Mobilization attempts are effective throughout the 4 cases,
but still spontaneous effect remains valid (based on the post-hoc
simulation of the equations with mobilization vars to Table 4 results (1 page before).
Figrure 2 Post-hoc simulation on the effects of IPE versus mobilization
year 2003
year 2001
Participation for LDP
Participation for DPJ
20%
15%
10%
5%
0%
0%
50%
100%
Support of IPE
no
Participation for LDP
Participation for DPJ
35%
30%
25%
20%
15%
10%
5%
0%
0%
yes
50%
100%
Support of IPE
mobilization attempt
no
yes
mobilization attempt
Effects for congruent cases; LDP for LDP & DPJ for DPJ
year 2005
year 2004
Participation for LDP
Participation for DPJ
25%
20%
15%
10%
5%
0%
0%
50%
Support of IPE
100%
no
yes
mobilization attempt
Participation for LDP
Participation for DPJ
20%
15%
10%
5%
0%
0%
50%
Support of IPE
100%
no
yes
mobilization attempt
Effect of mobilization on vote (H2C)
 Mobilization in terms of solicitation to vote for some specific party
has been thought of in Japanese context as the main factor.
 We added mobilization variables on to the models in Hypo 1
 The results show that Japanese voting behavior for conservative
party is no more the results of conformity pressure.
Table 6 Adding mobilization variables to predict votes
year 2001
Dependent variables
LDP vote
DPJ vote
coef.
coeff.
Gender
0.28 *
-0.17
Age
0.01
0.02 *
Education
-0.06
0.04
Years of residence
0.16 *
-0.03
Megalopolis vs. Small Town
0.00
0.07
Knowledge
-0.01
0.06 *
LDP support
0.84 ***
-0.37 **
DPJ support
-0.07
0.94 ***
Mobilization attempt from LDP
0.15 *
-0.14
Mobilization attempt from DPJ
-0.03
0.22 +
LDP-IPE ratio
0.84 ***
-0.55 *
DPJ-IPE ratio
-1.11 *
1.70 **
cutpoint 1
2.65 ***
2.83 ***
cutpoint 2
3.81 ***
4.12 ***
1164
1164
N
0.18
0.20
Pseudo R2
p value .05<p=<.1 +, .01<p=<.05 *, .001<p=<.01 **, p<.001 ***
year 2003
LDP vote
coef.
0.18
0.01 +
-0.01
0.17 *
0.06 *
-0.01
0.75 ***
-0.62 ***
0.15 +
-0.15
1.00 ***
-2.13 ***
2.13 ***
3.64 ***
1510
0.25
Year 2004
DPJ vote
coeff.
-0.33 *
-0.01 *
0.05
-0.04
-0.04
0.03
-0.24 **
1.02 ***
-0.13
0.09
-0.50 **
1.95 ***
-0.71
0.47
1510
0.20
LDP vote
coef.
-0.11
0.01
-0.04
0.22 ***
0.08 **
-0.13 +
0.92 ***
-0.81 ***
0.15
-0.41 **
1.06 ***
-0.84 *
2.39 ***
3.58 ***
1512
0.28
year 2005
DPJ vote
coeff.
-0.05
-0.01
0.13 *
-0.07
0.03
0.07
-0.20 **
1.14 ***
-0.01
0.51 ***
-0.34 +
1.42 ***
0.53
1.57 **
1512
0.20
LDP vote
coef.
-0.23 +
-0.01
0.04
0.08
0.02
-0.03 +
0.89 ***
-0.30 **
0.05
-0.18
1.38 ***
-0.99 ***
0.31
1.81 **
1230
0.26
DPJ vote
coeff.
0.25 +
0.00
0.02
-0.10
-0.01
-0.01
-0.21 *
0.91 ***
0.06
0.27 *
-1.22 ***
1.48 ***
0.38
1.45 *
1230
0.24
Conclusion on spontaneity
 Spontaneity effect hypothesis (H2)
 Clearly well supported.
 IPE push up voluntary comments on the PM or
Presidential candidates as well as political participation in
line with the IPE. Also the effect of IPE on political
participation was not suppressive on incongruent
participation with the IPE color.
 These findings were strengthened when we controlled the
mobilization variable.
 The power process working in IPE is not conformity
pressure, but more voluntary in nature.
 All in all, people behave under the high influence of
interpersonal environment, but it is not through the conformity
mechanism, which has been supposed to be the main
interpersonal force in Japanese political behavior for long time.
Their behavior and attitude are constructed through a more
voluntary and spontaneous basis, which is a good news for
Japanese democracy and social capital theory.
Comparison of the patterns
between Japan and the US
 Go back to Hypo 1 and see
the difference between the
countries.
The overall direction of the
IPE effect was consistent in
both countries. However, the
effect size was much larger
in the US.
Figure 2 Post hoc simulation of IPE effect
Probability of vote for
LDP or DPJ
Probability of vote for Bush
2 vote
1 vote
0 vote
1
1
0.8
0.8
0.6
0.6
0.4
0.4
0.2
0.2
IPE
0
0
0
0
J 1
P 1
LD PJ
PJ r DP DP
DP
fornd D
dL
d D e fo nd L
n
n
e
ot 0 a
1 a vot 0 a
1a
fv P
f J
J
P
LD lity o DP
DP
y o LD
ilit
i
b
b
a
a
ob
ob
Pr
Pr
ＩＰＥ
p
Re
0
m
d
an
p
Re
De
.25
an
1
d
m
De
e
.25 m 0
e
m
De nd D
d
a
n
a
1
.75 Rep
p
. 75
Re
Ti
RQ Institutional difference (two-party
system vs. multi-party systems) 1
 [Institutionalized visibility problem] The difference
between the Japanese and American data is attributable
to the difference between the two-party system and the
multi-party system with one dominant and other smaller
parties?
Limit the districts where the number of candidates
receiving most of the votes was equal to the number of
seats plus one.
: Close competition occurs when the number of popular
candidates is slightly higher than the number of seats in
the given district.
 This makes the competitive parties highly visible, i.e.
US-like institutional context arises.
RQ Institutional difference (two-party
system vs. multi-party systems) 2
 We selected competitive 22 districts out of 47
: Mt 80% of votes went to seat+1 (with DPJ candidate)
 (test 1) In these ‘competitive’ districts, as the substantial competition
increased the visibility of the candidates, the IPE effect would be
larger than when the same analysis was carried out for all
respondents?
 (test 2) To limit the districts where only one seat was being
contested, and two candidates received 80% of the vote
(More comparable to the American situation).
 In both of the two tests, we changed the dependent
variable slightly. Because we analyzed the effect
of seat competitiveness on a district level, we only focused on the
district vote (removed PR vote).
RQ Institutional difference (two-party
system vs. multi-party systems)
Table 4 Tests on the competitiveness effect
 The results were clear.
As Table 4 shows, in
these two types of
tests, the IPE effect on
the LDP vote or DPJ
vote was larger in the
competitive districts
than in the less
competitive ones
test 1
IPE
Competitive
Non competitive
Probability of vote for LDP
0.22
0.19
LDP 0 and DPJ 1
0.32
0.27
0.44
0.36
0.57
0.47
LDP 1 and DPJ 0
>
Probability of vote for DPJ
DPJ 0 and LDP 1
DPJ 1 and LDP 0
test 2
0.05
0.12
0.24
0.44
>
0.04
0.08
0.17
0.31
Competitive
Non competitive
IPE
Probability of vote for LDP
0.31
0.19
LDP 0 and DPJ 1
0.45
0.27
0.60
0.36
0.73
0.47
LDP 1 and DPJ 0
>
Probability of vote for DPJ
DPJ 0 and LDP 1
DPJ 1 and LDP 0
0.04
0.16
0.47
0.79
>
0.04
0.09
0.18
0.33
RQ Institutional difference
2003 result
 (The 2003 election was for H. of
Representative Election, i.e. SMD
is smaller).
 The results were clear again. As
Table shows, in this test, the IPE
effect on the LDP vote or DPJ vote
was larger in the competitive
districts than in the less
competitive ones.
• competitive=more than 88%
vote for the top 2 candidates in
the single seat district (not PR)
comptetitive less_competitive
Probability of vote for LDP
IPE LDP 0 and DPJ 1
0.07
0.06
0.21 > 0.17
0.49
0.40
LDP 1 and DPJ 0
0.78
0.68
Probability of vote for DPJ
DPJ 0 and LDP 1
0.12
0.39 >
0.75
DPJ 1 and LDP 0
0.93
0.15
0.36
0.63
0.84
Discussion and conclusion for RQ
 Further analyses revealed that whether politics
is organized around a two-party or multi-party
system with small parties may well effect the
impact of local personal political discourse.
 It was particularly revealing that Japanese
electoral districts that in some respects mimic a
US-type two-party system showed a stronger
IPE effect on LDP voters as well as DPJ voters.
 [Other analyses (not shown) prompted by the research questions
suggested that political cultural interpretations are not viable].
Discussion and conclusion
 In conclusion, the analyses showed differences in the effect of IPE,
the direction of which contradicts the collectivism interpretation of
Japanese political behavior.
 These differences may be largely attributable to institutional
difference between the US and Japan, specifically the political party
configuration (the two-party system versus the multi-party system
with small parties).
 Institutional context could be very consequential.
Context change makes party competition different, which in turn
changes the power of IPE on vote.
Japanese Electoral system change (from Multi-member single
nontransferable vote system to SMD dominant system) may have
increased the IPE influence.