2018/10/11

by GLOCOM

5%

47%

24%

24%

(n=1890, )

•––

•––

••

:polarization

• (polarization)–

•

••

Pew Research Center 2014a•

•

• 10

• 1972 712012 90 (American National Election Study

2015c).• Republican Democrat AI

Gentzkow, Shapiro and Taddy 2016

• 1960 unhappy5 2010 unhappy Republican

50 Democrat 30 (Iyengar et al. 2012).

•– BBC

https://www.bbc.com/japanese/37933945

28%

45%

7%

20%

(n=1890, )

:•

–•

–• 40%•

–

• selective exposure)–– SNS– like-minded people

•• (echo chamber)

––

Democrat Republican

•–

• Pew Research Center(2014b)

• Fox NewsNie(2010)

–• Boxell et

al(2017)•

Barbera(2015)

0

2000

4000

6000

8000

10000

12000

-3-2

.8-2

.6-2

.4-2

.2 -2-1

.8-1

.6-1

.4-1

.2 -1-0

.8-0

.6-0

.4-0

.2 00.

20.

40.

60.

8 11.

21.

41.

61.

8 22.

22.

42.

62.

8 3

(pol) (unit= )(n=78457, 10 )

•– 2017 8 10 2000

• pol– 10– 4

0 3 3

1 9 2 3 4 5 67 8 9 10

1= 2= 3= 4= 5= 6= 7= 8=

(rad)

•– rad=|pol-(-0.2)|

Weighted OLS VARIABLES rad

5 0.0109*** 0.025

(4.718) 0.0242*** 0.055

(10.05) LINE -0.0211*** -0.068

(-11.99) 0.00427** 0.013

(2.393) 0.0136*** 0.034

(6.360) -0.0173*** -0.040

(-6.929) -0.0184*** -0.052

(-9.208) 0.00840*** 0.028

(4.950)

female=1 -0.109*** -0.100 (-16.71)

( ) 0.00367*** 0.098 (15.83)

6 0.0273*** 0.068 (13.35)

-0.000853 -0.005 (-0.782) Constant 0.413*** (21.47) Observations 40,813 R-squared 0.047

t-statistics in parentheses *** p<0.01, ** p<0.05, * p<0.1

•

•

•

0.57

0.59 0.60

0.57

0.62

0.56

0.59

0.62

0.63 0.63

0.52

0.54

0.56

0.58

0.60

0.62

0.64

SNS (n=78,457)

0.47

0.51 0.54

0.58

0.66 0.69

0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

20 30 40 50 60 70

•– SNS

SNS•

–

•

–

• 5

–

0.39

0.65

0.44

0.52

0.30

0.50

0.22

0.43

0.14

0.28

0.21

0.25

0.10

0.24

0.13

0.18

0.05

0.17

0.08

0.14

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

20 30 40 50 60 70

9

• 2018 2 ( 2017 8• 1 54,334 (

55– 3861 50,473

•– 10 poli– ( radi

–• pchangei=poli2 – poli1• Rchangei=radi2 radi1

• control)• treatment)

––

1 2 3 4 5

FaceBook1=

2= 3= 4= 5=

1= 33,446 1,366 219 76 1732= 1,303 3,847 595 153 1543= 151 815 945 274 2234= 71 219 400 440 3435= 185 270 324 508 3,973

1

33,446

7,430407

468

(

• Facebook, Twitter,

• LINE( )

– LINE

0.002

-0.004

-0.011

-0.006 -0.003

0.003 0.000

-0.001

-0.020

-0.015

-0.010

-0.005

0.000

0.005

0.010

0.015

0.020

FB Twitter LINE NetNews Blog TVNews WidShow Newspaper

Change of polarization by media usage: keep_usingdifference from no_use

difference

-0.0026 -0.0042

0.0172

-0.0034 -0.0024 -0.0017

-0.0084

-0.0136

-0.0200

-0.0150

-0.0100

-0.0050

0.0000

0.0050

0.0100

0.0150

0.0200

FB Twitter LINE NetNews Blog TVNews WidShow Newspaper

Change of ploarization by media usage: start_usingdifference from no_use

difference

FB Twitter

FB Twitter

•

•

•

•

• 27–

•

-1.35 -1.22 -1.18 -1.17

-1.02 -0.92 -0.92

-0.76 -0.66

-0.54 -0.51 -0.51

-0.43 -0.32 -0.27

0.08 0.20 0.22

0.40 0.57 0.62 0.68 0.70

0.99 1.07

1.36 1.60

-2.00 -1.00 0.00 1.00 2.00

(174)(133)(185)(178)(137)(231)

(79)(197)(343)(313)(205)(126)

(89)(135)(236)(129)(922)

(99)(20)(95)

(159)(531)(376)(188)(361)(204)

(88)

27

•

•

•

• 103 4 1103

•

34,787 2,466 1,273 759 568 385 315 250 211 166 128 94 72 65 54 53

12 1 2 1 2 1 4 8 19

11 2 1 1 1 2 2 6 4 7 6 3 35

10 1 2 1 5 2 6 5 6 4 7 10 11 60

9 4 1 3 3 5 2 6 8 9 10 14 8 9 12 7 16 117

8 9 7 8 8 13 4 7 17 24 21 14 12 8 11 9 6 178

7 21 12 16 10 18 25 28 23 38 29 15 11 11 16 5 4 282

6 23 19 27 23 36 42 46 46 38 28 21 15 3 2 6 2 377

5 43 52 50 64 62 63 61 38 29 23 14 16 8 4 2 2 531

4 111 103 116 122 97 65 44 38 20 15 14 3 3 1 752

3 236 283 192 156 112 60 39 24 16 12 6 5 6 2 1 1 1,151

2 683 408 273 146 102 52 34 11 14 5 4 8 6 1 1,747

1 1,915 648 283 130 59 34 24 14 10 7 8 3 4 1 3,140

0 31,742 932 305 93 64 37 25 25 9 8 9 3 4 1 33,257

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 41,646

0.68 0.32 1.000.47 0.53 1.00

16% >0.69 0.31 1.000.34 0.66 1.00

•

• 32%47%

– 13

– Barbera(2015) Twitter US 3 Spain 4 Germany 4

•

•–– Hanada

•

•–

–

•

•

–

•

• 3~4

•

•

•––

–

•

–

• Pew Research Center, 2014a, "Political Polarization in the American Public: How Increasing Ideological Uniformity and Partisan Antipathy Affect Politics, Compromise and Everyday Life," http://assets.pewresearch.org/wp-content/uploads/sites/5/2014/06/6-12-2014-Political-Polarization-Release.pdf

• Pew Research Center, 2014b, "Political Polarization and Media Habits: From Fox News to Facebook, How Liberals and Conservatives keep Up with Politics," http://assets.pewresearch.org/wp-content/uploads/sites/13/2014/10/Political-Polarization-and-Media-Habits-FINAL-REPORT-7-27-15.pdf

• Nie, N., Miller, D., Golde, S., Butler, D., Winneg, K., 2010. The world wide web and the U.S. political news market. American Journal of Political Science 54, 428–439.

• Boxell, Levi, Matthew Gentzkow, Jesse M. Shapiro 2017 "Is the Internet Causing Political Polarization? Evidence from Demographics" NBER Working Paper 23258

• Barberá, Pablo, 2015, "How Social Media Reduces Mass Political Polarization. Evidence from Germany, Spain, and the United States," Working paper

• http://pablobarbera.com/static/barbera polarization APSA.pdf