Based on our recent research regarding the link between income divergence and ideological polarization in Korea. We analyze the results of a survey conducted in 2018 in Korea that covers 2000 respondents.

1. Alexandre Repkine, Konkuk University
Hyunchool Lee, Konkuk University
The World Congress for Korean Politics and Society
Koryo University, 2021

2. Ideological Polarization
Ideological Polarization
Political Unrest Social Conflict Inefficient
Supply of
Public Goods
• Ideological polarization on the rise in the US and Europe, what are the factors?
• Korea has also recently become more polarized
Introduction

3. Ideological Polarization in Korea
 Before the democratization event in 1987
 Right-wing political views dominate
 Not much space for political cleavages
 After 1987
 Political parties seek new dividing lines
 Korean regionalism picks up
 Polarization increases
 External factors driving polarization
 The Asian financial crisis of 1997
 Global financial crisis of 2008
Introduction

4. Idiosyncrasies of Korean Polarization
 Korea is one of the most homogeneous societies in
the world
 No racial dividing lines
 No religious cleavages
 Immigration policies not important for most of history
 Income inequality is one of the major dividing
factors
 Significant part of population surviving on less than a
median income (median income is computed for
households)
Introduction

5. Measuring Ideological Polarization
 Dalton’s liberal-conservative scale
 Ideological scores assigned to oneself or an entity, e.g.
political party
 Typically ranging from zero (very liberal) to ten (very
conservative)
 Polarization measures have long been used in
economics as key determinants of social conflict
 Survey material to analyze ideological scores
 Voter polarization
 Based on self-assigned scores
 Political party polarization
 Based on scores assigned to preferred political parties
Introduction

6. Income Inequality and
Ideological Polarization
 Median voter model (Meltzer and Richard, 1981)
 Alesina and Rodrik (1994)
Ideological Polarization and Income Inequality
Income
Inequality
Social Demand for
Redistribution
Ideological
Polarization
"in less equal societies more redistribution is sought
by a majority of the population."

7. Demand for Redistribution and
Polarization
 In unequal societies the mean income is less than the
median income
 As a result, the median voter will vote for redistribution
of income toward the poor
 The wealthier voters will oppose redistribution
 Voter polarization is the likely result
 Political party polarization follows as parties are trying
to adapt to the voters’ preferences
Ideological Polarization and Income Inequality

8. Economic Inequality in Korea
 Two major events contributing to rising income
inequality in Korea
 1997 Asian financial crisis
 2008 global financial crisis
 Asset inequality appears to contribute more to economic
inequality compared to business income inequality
 Subjective perception of one’s income is an important
factor affecting voting behavior, Lee and Kwon (2015)
Ideological Polarization and Income Inequality

9. Survey Design
 Center for Research on Future Politics, Myongji University
 2018, after Korean local elections
 76 questions
 Voting participation
 General political attitude
 Political awareness
 Attitudes toward political parties
 Attitudes on government and economy
 Attitudes on social, security, environmental issues
 Males (49.7%), females (50.3%): equal representation
 Half of respondents from Seoul, Gyeonggi-do, and Busan
 Median age: 47
 Irregular workers 10.7%, more than half have a job or are housewives
Survey Description and Summary Statistics

10. The Ideological Placement of Survey Respondents
and Political Parties, 2018
Response Variable,
Scores on a
Liberal-Conservative Scale
Mean Standard
Deviation
Skewness Scale
Democratic Party of Korea 3.19 2.23 0.45 0-10
Liberty Korea Party 7.63 2.75 -1.06 0-10
Bareunmirae Party 5.73 2.06 0.04 0-10
Party for Democracy and Peace 4.39 2.08 0.03 0-10
Justice Party 3.04 2.37 0.45 0-10
Self-placement score 4.62 2.05 0.12 0-10
Survey Description and Summary Statistics
Most liberal: score zero
Most conservative: score ten

11.  Center-Left voters
support DP, PDP, JP
(3.63)
 Right-wing voters
support LKP (7.28)
 Centrist voters
support BP (5.34)
Is Korean society ideologically polarized?
Korean Voters’ Self-Assigned Ideological Scores
Downs (1957) ideological continuum:
Liberal (score Zero) to Conservative (score Ten)
Is Korean society polarized? We
need a comprehensive measure
of ideological polarization.

12. Measuring Ideological Polarization
A Measure of Ideological Polarization Related to the Incidence of Conflict
2
1 1
N N
i j i j
i j
P K v v p p
 
 

Montalvo and Reynal-Querol (2005)
 
1 2
, ,..., N
p p p p

Vector of political
parties’ scores / self-
assigned scores
 
1 2
, ,..., N
v v v v

Vector of voter
group shares
2
1
N
i
i
K v



 
  
 

Normalizing
constant,
following Draca
and Schwarz (2019)
• Varies between zero and
one
• corresponds to two
equal-sized groups with
opposite beliefs: serious
conflict
• in case of uniform
distribution of beliefs: no
conflict
1
P 
0
P 

13. Regional Measures of Party and Voter Polarization
Polarization
Region Political Party Voter
All Regions 8.06% 5.78%
Seoul 8.31% 5.77%
Busan 7.35% 6.48%
Daegu 10.14% 9.76%
Incheon 8.11% 6.61%
Gwangju 0.66% 2.49%
Daejeon 11.14% 8.90%
Ulsan 10.47% 7.77%
Gyeonggi-do 8.37% 5.84%
Gangwon-do 13.48% 11.07%
Chungcheong-buk-do 3.44% 4.90%
Chuncheong-nam-do 7.29% 5.39%
Jeolla-buk-do 2.03% 1.31%
Jeolla-nam-do 3.09% 1.47%
Gyeongsang-buk-do 12.30% 8.59%
Gyeongsang-nam-do 10.84% 9.00%
Jeju-do 7.46% 5.71%
Source: authors' calculations based on the results of the survey
• Neither political
party nor voter
polarization is
close to 100%
• Two measures
correlated at 94%
• Honam much less
polarized
compared to
Yeongnam

14. Individual Voters’
Ideological Divergence
Individual Measures of Party and Voter Polarization
k k
i
k
i k
S
S S
D


 
k
i
S
Ideological score
associated with
individual i in region k
k
S
Regional average of
ideological scores
k
S

Regional standard
deviation of
ideological scores
• Higher value of : voters whose
ideological orientation diverges a lot
from the regional sentiment
• Prevalence of ideologically divergent
voters contributes to social
polarization
k
i
D


15. Summary of Individual Measures of
Ideological Polarization
Individual Measures of Party and Voter Polarization
Individual Ideological Polarization
Region Political Party Voter
Median SD Min Max Median SD Min Max
All Regions 0.72 0.55 0.01 2.32 0.55 0.66 0.01 2.65
Seoul 0.76 0.54 0.02 2.22 0.74 0.63 0.23 2.76
Busan 0.77 0.57 0.01 2.32 0.60 0.68 0.13 2.51
Daegu 0.83 0.59 0.13 1.96 0.46 0.73 0.01 2.34
Incheon 0.74 0.58 0.05 2.03 0.39 0.71 0.10 2.54
Gwangju 0.66 0.79 0.09 2.35 0.62 0.60 0.14 2.98
Daejeon 0.87 0.51 0.20 1.80 0.56 0.52 0.03 2.15
Ulsan 0.77 0.84 0.10 2.25 0.38 0.68 0.18 3.21
Gyeonggi-do 0.71 0.53 0.02 2.07 0.67 0.67 0.17 2.65
Gangwon-do 0.92 0.50 0.02 1.53 0.25 0.78 0.02 2.45
Chungcheong-buk-do 0.50 0.59 0.03 2.38 0.24 0.68 0.24 2.67
Chuncheong-nam-do 0.59 0.60 0.17 2.47 0.27 0.67 0.25 2.84
Jeolla-buk-do 0.72 0.52 0.04 2.43 0.51 0.58 0 2.04
Jeolla-nam-do 0.74 0.60 0.05 2.80 0.55 0.63 0.02 3.19
Gyeongsang-buk-do 0.65 0.54 0 1.63 0.59 0.69 0.08 2.48
Gyeongsang-nam-do 0.73 0.52 0.13 1.63 0.84 0.66 0.02 2.16
Jeju-do 0.69 0.57 0.05 2.28 0.42 0.71 0.10 2.51
Source: authors' calculations based on the results of the survey
• Ideological
scores are less
than one
standard
deviation away
from the mean
• Honam and
Chungcheong
feature more
individual
divergence

16. Gini Coefficient
 Gini coefficient is a standard way of measuring the
extent of inequality of income distribution
Inequality of Income Distribution
   
1 1
1
2
n n
i j i j
i j
G f y f y y y
  
 

N is the number of
income classes
i
y Representative
income of income
class i
 
i
f y Population share
in income class i
 
1
n
i i
i
y f y


  Average income
• Varies between zero and unity
• Increases with more income inequality
• Is a particular case of the polarization measure in
Montalvo and Reynal-Querol (2005)
• Recent CIA estimate for Korea: 0.36
• Recent estimate for Sweden: 0.25

17. Regional Gini Coefficients in Korea
Income Inequality in Korea
Region Gini
Coefficient
Region Gini
Coefficient
All Regions 0.271
Seoul 0.270 Gangwon-do 0.250
Busan 0.288 Chungcheong-buk-do 0.248
Daegu 0.275 Chuncheong-nam-do 0.245
Incheon 0.240 Jeolla-buk-do 0.266
Gwangju 0.321 Jeolla-nam-do 0.275
Daejeon 0.243 Gyeongsang-buk-do 0.287
Ulsan 0.327 Gyeongsang-nam-do 0.266
Gyeonggi-do 0.261 Jeju-do 0.258
Regional Gini coefficients do not point to
an acute problem of income inequality.

18. Individual Income Divergence
Income Inequality in Korea
k
i
I

• Number of standard deviations
by which voter i’s income diverges from
region k’s mean
• By construction, income divergence is
independent of the regional Gini
• Similarly to the ideological scores,
Korean incomes tend to cluster around
the regional mean
Region Income Divergence
Median SD Min Max
All Regions 0.69 0.62 0.02 2.76
Seoul 0.71 0.62 0.07 2.27
Busan 0.69 0.59 0.13 2.58
Daegu 0.75 0.59 0.07 2.93
Incheon 0.51 0.67 0.06 3.21
Gwangju 0.66 0.59 0.06 2.19
Daejeon 0.45 0.64 0.01 3.06
Ulsan 0.68 0.58 0.10 2.64
Gyeonggi-do 0.81 0.63 0.03 2.55
Gangwon-do 0.54 0.72 0.06 3.78
Chungcheong-buk-do 0.52 0.66 0.03 3.28
Chuncheong-nam-do 0.56 0.65 0.11 3.27
Jeolla-buk-do 0.54 0.59 0.01 2.64
Jeolla-nam-do 0.68 0.64 0.15 3.08
Gyeongsang-buk-do 0.71 0.60 0.09 2.48
Gyeongsang-nam-do 0.63 0.63 0.16 3.07
Jeju-do 0.76 0.58 0.08 2.46

19. Empirical Specification
Ideological Polarization and Income Inequality
0 1 2
k k k k k k k
i i i i
D I Gini X H Y
   
         
k
i
D
 Individual extent of ideological divergence: self-assigned or party scores
k
i
I
 Individual income divergence
k
Gini Regional income inequality: Gini coefficient
k
i
X Individual controls:
• Logarithm of income
• Gender
• Age
• Education
• Relative well-being
Dummies:
• Retirement
• Housewife
• Student
• Unemployed
k k
H Y

Honam and
Yeongnam dummies
k
i
 i.i.d. normal errors

20. Divergence of Preferred Political Party Scores
Dependent Variable: Divergence of Preferred Political Party Scores
Determinants (1) (2) (3) (4) (5) (6) (7)
Logarithm of Inco
me
-0.060
(0.035)*
-0.062
(0.035)*
-0.052
(0.035)
-0.081
(0.039)**
-0.079
(0.039)*
-0.076
(0.039)**
-0.096
(0.040)**
Income Divergence 0.015
(0.028)
0.017
(0.028)
0.019
(0.028)
0.019
(0.028)
0.019
(0.028)
0.018
(0.028)
0.031
(0.028)
Gini 0.370
(0.757)
0.121
(0.790)
0.147
(0.790)
0.097
(0.789)
0.091
(0.791)
0.128
(0.792)
0.177
(0.789)
Gender 0.043
(0.035)
0.048
(0.035)
0.050
(0.035)
0.054
(0.040)
0.054
(0.040)
0.051
(0.040)
Age 0.004
(0.001)***
0.004
(0.001)***
0.004
(0.001)***
0.004
(0.001)***
0.004
(0.001)***
0.004
(0.001)***
Education -0.050
(0.035)
-0.058
(0.035)*
-0.058
(0.035)*
-0.062
(0.036)*
-0.063
(0.036)*
Relative well-being 0.022
(0.012)*
0.021
(0.012)*
0.021
(0.012)
0.018
(0.012)
Retired 0.036
(0.081)
0.033
(0.081)
0.023
(0.080)
Housewife 0.018
(0.056)
0.019
(0.056)
0.001
(0.056)
Student 0.070
(0.084)
0.046
(0.085)
Unemployed -0.243
(0.084)***
Yeongnam 0.028
(0.041)
0.025
(0.041)
0.026
(0.041)
0.023
(0.041)
0.023
(0.041)
0.024
(0.041)
0.029
(0.041)
Honam -0.059
(0.049)
-0.071
(0.049)
-0.070
(0.049)
-0.078
(0.049)
-0.078
(0.049)
-0.077
(0.049)
-0.078
(0.049)
Constant 0.829
(0.159)***
0.596
(0.174)***
0.711
(0.192)***
0.761
(0.200)***
0.768
(0.202)***
0.711
(0.196)***
0.801
(0.204)***
No. Obs. 976 976 976 976 976 976 976
Note: standard errors in parentheses. (***), (**), and (*) stand for 1%, 5%, and 10% significance levels, respectively.

21. Results:
Divergence of Political Party Scores
 Wealthier voters view parties less polarized
 Regional issues do not seem important
 Honam and Yeongnam dummies not significant
 Older voters have a more polarized view of the political
parties
 More education associated with less polarized views
 Income divergence and Gini coefficients: no effect
 Demand for redistribution is a function of income level, not
relative income
Divergence of Preferred Political Party Scores

22. Divergence of Self-Assigned Ideological Scores
Dependent Variable: Divergence of Self-Assigned Ideological Scores
Determinants (1) (2) (3) (4) (5) (6) (7)
Logarithm of Income 0.013
(0.028)
0.012
(0.028)
0.008
(0.029)
-0.011
(0.032)
-0.015
(0.032)
-0.013
(0.032)
-0.021
(0.033)
Income Divergence 0.044
(0.024)*
0.046
(0.024)*
0.045
(0.024)*
0.047
(0.024)*
0.046
(0.024)*
0.045
(0.024)*
0.052
(0.024)**
Gini 0.391
(0.694)
0.385
(0.693)
0.379
(0.694)
0.351
(0.694)
0.338
(0.694)
0.354
(0.694)
0.367
(0.694)
Gender 0.061
(0.030)*
*
0.062
(0.030)**
0.060
(0.030)**
0.060
(0.030)**
0.044
(0.034)
0.042
(0.034)
0.043
(0.034)
Age 0.002
(0.001)**
0.002
(0.001)**
0.002
(0.001)**
0.003
(0.001)**
0.003
(0.001)**
0.003
(0.001)**
Education 0.020
(0.029)
0.014
(0.030)
0.012
(0.030)
0.007
(0.030)
0.007
(0.030)
Relative well-being 0.014
(0.010)
0.016
(0.010)
0.015
(0.010)
0.014
(0.010)
Retired -0.031
(0.071)
-0.034
(0.071)
-0.037
(0.071)
Housewife -0.048
(0.044)
-0.048
(0.044)
-0.055
(0.045)
Student 0.076
(0.073)
0.060
(0.073)
Unemployed -0.111
(0.065)*
Yeongnam -0.023
(0.034)
-0.028
(0.034)
-0.028
(0.034)
-0.030
(0.034)
-0.031
(0.034)
-0.031
(0.034)
-0.029
(0.034)
Honam 0.016
(0.045)
0.009
(0.045)
0.008
(0.045)
0.005
(0.045)
0.004
(0.045)
0.005
(0.045)
0.004
(0.045)
Constant 0.587
(0.151)
0.491
(0.158)***
0.445
(0.172)***
0.428
(0.172)**
0.438
(0.174)**
0.421
(0.174)**
0.453
(0.175)***
No. Obs. 1993 1993 1993 1993 1993 1993 1993
Note: standard errors in parentheses. (***), (**), and (*) stand for 1%, 5%, and 10% significance levels, respectively.

23. Results:
Divergence of Self-Assigned Scores
 Region-level income inequality not significant
 Regional issues not present
 Older voters likely to hold more polarized views of
themselves
 Income level is not affecting self-assigned scores’
divergence
 However, income divergence is significant
Divergence of Self-Assigned Ideological Scores

24. Economic Disadvantage and
Demand for Redistribution
1. Bottom income brackets want redistribution
2. Top income brackets resist redistribution
3. More income polarization results in more
ideological polarization
 Define to equal 1 if respondent i supported a
political party of X points or higher
 PR9=1 if a voter’s preferred party is assigned score 9 or
higher (very conservative)
Income Inequality and Demand for Redistribution
i
PRX

25. Ordered Probit Specification
Income Inequality and Demand for Redistribution
   
*
1 2
Pr 1 k k
i i i i i i
P I Gini X H Y
  
         
*
i
P Is the dummy variable PRX or PLX for PRX=8,9,10 and PLX=0,1,2
 
  Cumulative standard normal distribution function
,
k
i
I
 Income divergence
i
X Individual controls:
• Logarithm of income
• Gender
• Age
• Education
• Relative well-being
Dummies:
• Retirement
• Housewife
• Student
• Unemployed
k k
H Y
 Honam, Yeongnam dummies
k
Gini Regional income inequality

26. Ordered Probit Results
Income Inequality and Demand for Redistribution
Probability of the Preferred Political
Party's Ideological Score Being
Determinants Less than
or Equal to
Greater than
or Equal to
0 1 2 8 9 10
Logarithm of Income -0.160
(0.057)***
-0.078
(0.056)
-0.021
(0.055)
-0.141
(0.057)**
-0.143
(0.058)**
-0.138
(0.059)***
Income Divergence 0.074
(0.043)*
0.009
(0.042)
-0.040
(0.041)
0.079
(0.043)*
0.097
(0.044)**
0.074
(0.044)*
Gini -0.685
(1.234)
1.372
(1.197)
0.073
(1.179)
-2.308
(1.228)*
-2.874
(1.259)**
-3.274
(1.280)**
Gender -0.147
(0.060)**
-0.082
(0.059)
-0.051
(0.058)
-0.108
(0.060)*
-0.173
(0.061)***
-0.184
(0.062)***
Age -0.006
(0.002)***
-0.004
(0.002)*
-0.001
(0.002)
0.004
(0.002)*
0.001
(0.002)
-0.002
(0.002)
Education -0.179
(0.054)***
-0.154
(0.052)***
-0.090
(0.051)*
-0.100
(0.053)*
-0.070
(0.054)
-0.080
(0.055)
Relative well-being -0.023
(0.018)
-0.017
(0.018)
-0.023
(0.017)
-0.006
(0.018)
-0.033
(0.018)*
-0.049
(0.019)***
Retired 0.190
(0.125)
0.106
(0.122)
0.102
(0.120)
0.080
(0.124)
0.270
(0.126)**
0.351
(0.128)***
Housewife 0.110
(0.078)
0.127
(0.076)*
0.044
(0.075)
0.085
(0.078)
0.052
(0.080)
0.100
(0.081)
Student -0.081
(0.131)
-0.075
(0.127)
0.055
(0.125)
0.118
(0.129)
0.032
(0.133)
0.015
(0.134)
Unemployed -0.103
(0.115)
-0.149
(0.113)
-0.106
(0.111)
-0.001
(0.114)
-0.018
(0.117)
0.037
(0.119)
Yeongnam 0.105
(0.060)*
0.046
(0.058)
-0.008
(0.057)
0.069
(0.059)
0.130
(0.060)**
0.138
(0.061)**
Honam -0.071
(0.081)
0.106
(0.078)
0.210
(0.077)***
-0.394
(0.082)***
-0.404
(0.084)***
-0.398
(0.085)***
No. Obs. 1993 1993 1993 1993 1993 1993
Note: standard errors in parentheses. (***), (**), and (*) stand for 1%, 5%, and 10% significance levels, respectively.
The ideological score of 0 corresponds to the most liberal stance with the score of 10 characterizing the most conservative attitudes.
• Income divergence induces
voting for both right-and left-
wing parties
• Wealthier individuals tend to
support more moderate
political parties
• Redistribution driven by
• Bottom income
• Top income?
• Two opposing
effects
• More education not conducive
to supporting left-wing parties
• Honam less likely to support
conservative parties, as opposed
to Yeongnam

27. Conclusion
 The scope of social cleavages is rather narrow in Korea, one of the world’s most
homogeneous countries
 Income inequality appears to be a major factor driving ideological polarization
in Korea
 Revealed preference approach based on a survey with 2000 respondents
conducted in 2018
 Demand for income redistribution seems to be supported by the data
 Higher extent of one’s income divergence from regional mean increases
probability of voting for a more “extreme” political party
 Income divergence appears to drive self-assigned ideological divergence
 Economic security seems to reduce demand for redistribution, thus decreasing
the extent of ideological polarization
 Regionalism does not seem to play an important role