Growth Curve Models of Political Discussion (Standard Errors Within Parentheses)

Online Appendix

FigureA.1

Research design

Table A.1

Growth curve models of political discussion (standard errors within parentheses)

Number of alters with whom politics discussed / (Highest) frequency of political discussiona
(I) / (II) / (III) / (IV)
Intercept equation
Non-participants (000) / Ref. / Ref. / Ref. / Ref.
Early joiners (011) / 0.475** / 0.299** / 0.793** / 0.571**
(0.108) / (0.101) / (0.176) / (0.182)
Incidental participants (010) / 0.099 / 0.012 / 0.013 / -0.081
(0.104) / (0.094) / (0.174) / (0.177)
Late joiners (001) / 0.078 / -0.008 / 0.045 / 0.058
(0.106) / (0.097) / (0.181) / (0.181)
Persistent participants (111) / 0.557** / 0.309** / 0.826** / 0.435**
(0.070) / (0.065) / (0.121) / (0.124)
Early leavers (100) / 0.298** / 0.203* / 0.385* / 0.353*
(0.087) / (0.080) / (0.151) / (0.153)
Late leavers (110) / 0.324** / 0.196* / 0.534** / 0.387*
(0.092) / (0.085) / (0.158) / (0.160)
Age / -0.006** / 0.015**
(0.002) / (0.003)
Education / 0.266** / 0.363**
(0.022) / (0.040)
Gender / 0.185** / -0.179*
(0.051) / (0.091)
Income / 0.008 / 0.008
(0.007) / (0.013)
Occup. status: intermediate / 0.239** / 0.194
(0.059) / (0.101)
Occup. status: high / 0.191* / 0.204
(0.092) / (0.156)
Agreeableness / 0.153** / 0.121*
(0.031) / (0.059)
Conscientiousness / -0.036 / -0.040
(0.030) / (0.055)
Extraversion / 0.100** / 0.102
(0.028) / (0.053)
Intellect / Openness / 0.198** / 0.472**
(0.033) / (0.061)
Neuroticism / -0.035 / 0.055
(0.027) / (0.050)
Constant / 2.001** / 1.053** / - / -
(0.050) / (0.151)
Slope equation
Non-participants (000) / Ref. / Ref. / Ref. / Ref.
Early joiners (011) / 0.079* / 0.084* / 0.080 / 0.056
(0.037) / (0.037) / (0.061) / (0.066)
Incidental participants (010) / 0.031 / 0.032 / 0.081 / 0.060
(0.035) / (0.035) / (0.064) / (0.068)
Late joiners (001) / 0.032 / 0.033 / 0.082 / 0.072
(0.037) / (0.037) / (0.065) / (0.071)
Persistent participants (111) / 0.015 / 0.023 / 0.025 / 0.028
(0.025) / (0.025) / (0.040) / (0.043)
Early leavers (100) / -0.003 / 0.001 / -0.060 / -0.058
(0.033) / (0.033) / (0.051) / (0.054)
Late leavers (110) / 0.028 / 0.030 / 0.045 / 0.042
(0.033) / (0.033) / (0.056) / (0.061)
Age / 0.002** / 0.001
(0.001) / (0.001)
Education / -0.002 / 0.015
(0.008) / (0.014)
Gender / 0.030 / 0.089*
(0.020) / (0.035)
Income / -0.000 / -0.001
(0.001) / (0.001)
Occup. status: intermediate / -0.058* / -0.042
(0.022) / (0.037)
Occup. status: high / -0.064 / -0.055
(0.035) / (0.058)
Agreeableness / -0.009 / 0.012
(0.012) / (0.022)
Conscientiousness / -0.008 / -0.005
(0.012) / (0.020)
Extraversion / 0.015 / -0.003
(0.011) / (0.019)
Intellect / Openness / -0.031** / -0.046*
(0.012) / (0.023)
Neuroticism / -0.009 / -0.016
(0.011) / (0.018)
Constant / -0.052** / -0.175* / -0.041 / -0.228
(0.017) / (0.057) / (0.032) / (0.108)
Observations / 4232 / 4232 / 4232 / 4232

*p < 0.05, **p < 0.01.

a Growth curve models with an ordered logit link function (GSEM in Stata13). Cutpoints were fixed to be similar across the waves. Additional analyses on the separate waves showed deviations from the proportional odds assumption of the ordered logit regression (see Long & Freese 2001). A Brant test showed that the control variables (not shown in Table 2) were mostly responsible for this and therefore they have to be interpreted with caution.

bControl variables: personality (big 5), education, income, occupational status, gender, and age.

Table A.2

Growth curve models of political interest (standard errors within parentheses)

(I) / (II)
Intercept equation
Non-participants (000) / Ref. / Ref.
Early joiners (011) / 0.465** / 0.186
(0.143) / (0.120)
Incidental participants (010) / 0.123 / -0.067
(0.143) / (0.122)
Late joiners (001) / -0.067 / -0.137
(0.151) / (0.120)
Persistent participants (111) / 0.724** / 0.256**
(0.100) / (0.084)
Early leavers (100) / -0.105 / -0.092
(0.128) / (0.106)
Late leavers (110) / 0.335* / 0.096
(0.131) / (0.111)
Age / 0.053**
(0.002)
Education / 0.305**
(0.026)
Gender / -0.990**
(0.067)
Income / -0.001
(0.004)
Occup. status: intermediate / 0.111
(0.072)
Occup. status: high / 0.485**
(0.112)
Agreeableness / 0.124**
(0.012)
Conscientiousness / 0.116**
(0.039)
Extraversion / 0.176**
(0.040)
Intellect / Openness / 0.486**
(0.043)
Neuroticism / 0.018
(0.036)
Constant / 5.504** / 3.507**
(0.072) / (0.196)
Slope equation
Non-participants (000) / Ref. / Ref.
Early joiners (011) / 0.064 / 0.052
(0.042) / (0.042)
Incidental participants (010) / -0.019 / -0.027
(0.039) / (0.039)
Late joiners (001) / 0.093* / 0.081
(0.043) / (0.043)
Persistent participants (111) / 0.035 / 0.022
(0.026) / (0.027)
Early leavers (100) / -0.006 / -0.010
(0.035) / (0.035)
Late leavers (110) / -0.053 / -0.056
(0.035) / (0.035)
Age / -0.001
(0.001)
Education / 0.030**
(0.009)
Gender / -0.033
(0.022)
Income / -0.000
(0.001)
Occup. status: intermediate / -0.016
(0.025)
Occup. status: high / -0.014
(0.036)
Agreeableness / 0.024
(0.013)
Conscientiousness / -0.029*
(0.013)
Extraversion / 0.001
(0.012)
Intellect / Openness / -0.038**
(0.013)
Neuroticism / -0.026
(0.012)
Constant / -0.122** / -0.131*
(0.020) / (0.067)
Observations / 4232 / 4232

*p < 0.05, **p < 0.01.

a Control variables: personality (big 5), education, income, occupational status, gender, and age.

Table A.3

Growth curve models of political efficacy (standard errors within parentheses)

(I) / (II)
Intercept equation
Non-participants (000) / Ref. / Ref.
Early joiners (011) / 0.353** / 0.195*
(0.098) / (0.088)
Incidental participants (010) / 0.204* / 0.109
(0.095) / (0.082)
Late joiners (001) / -0.039 / -0.125
(0.101) / (0.088)
Persistent participants (111) / 0.633** / 0.366**
(0.070) / (0.064)
Early leavers (100) / 0.179* / 0.114
(0.087) / (0.076)
Late leavers (110) / 0.248** / 0.130
(0.090) / (0.081)
Age / 0.001
(0.002)
Education / 0.323**
(0.021)
Gender / -0.299**
(0.048)
Income / 0.004
(0.007)
Occup. status: intermediate / 0.080
(0.054)
Occup. status: high / 0.284**
(0.089)
Agreeableness / 0.029
(0.028)
Conscientiousness / 0.023
(0.028)
Extraversion / 0.076**
(0.028)
Intellect / Openness / 0.318**
(0.030)
Neuroticism / -0.066*
(0.026)
Constant / 2.009** / 1.291**
(0.048) / (0.142)
Slope equation
Non-participants (000) / Ref. / Ref.
Early joiners (011) / 0.024 / 0.026
(0.034) / (0.034)
Incidental participants (010) / -0.039 / -0.033
(0.033) / (0.033)
Late joiners (001) / 0.007 / 0.008
(0.033) / (0.033)
Persistent participants (111) / -0.028 / -0.017
(0.023) / (0.024)
Early leavers (100) / -0.057 / -0.061*
(0.029) / (0.029)
Late leavers (110) / -0.002 / 0.005
(0.030) / (0.030)
Age / -0.002**
(0.001)
Education / -0.011
(0.007)
Gender / -0.011
(0.018)
Income / 0.001
(0.002)
Occup. status: intermediate / -0.027
(0.020)
Occup. status: high / -0.039
(0.031)
Agreeableness / 0.005
(0.011)
Conscientiousness / -0.012
(0.011)
Extraversion / 0.008
(0.010)
Intellect / Openness / 0.013
(0.011)
Neuroticism / -0.000
(0.010)
Constant / 0.004 / 0.179**
(0.016) / (0.053)
Observations / 4232 / 4232

*p < 0.05, **p < 0.01.

a Control variables: personality (big 5), education, income, occupational status, gender, and age.

Table A.4

Growth curve models of political action (standard errors within parentheses)

(I) / (II)
Intercept equation
Non-participants (000) / Ref. / Ref.
Early joiners (011) / 0.258** / 0.189**
(0.059) / (0.058)
Incidental participants (010) / 0.134** / 0.084
(0.049) / (0.046)
Late joiners (001) / 0.104* / 0.076
(0.050) / (0.048)
Persistent participants (111) / 0.454** / 0.347**
(0.041) / (0.039)
Early leavers (100) / 0.173** / 0.150**
(0.043) / (0.042)
Late leavers (110) / 0.279** / 0.218**
(0.052) / (0.048)
Age / 0.004**
(0.001)
Education / 0.068**
(0.013)
Gender / -0.204**
(0.031)
Income / -0.002
(0.002)
Occup. status: intermediate / 0.084**
(0.032)
Occup. status: high / 0.291**
(0.062)
Agreeableness / 0.007
(0.019)
Conscientiousness / -0.052**
(0.017)
Extraversion / 0.083**
(0.017)
Intellect / Openness / 0.159**
(0.019)
Neuroticism / 0.065**
(0.016)
Constant / 0.383** / 0.248**
(0.021) / (0.085)
Slope equation
Non-participants (000) / Ref. / Ref.
Early joiners (011) / 0.016 / 0.022
(0.021) / (0.021)
Incidental participants (010) / -0.024 / -0.019
(0.017) / (0.017)
Late joiners (001) / -0.008 / -0.006
(0.018) / (0.018)
Persistent participants (111) / -0.020 / -0.012
(0.013) / (0.013)
Early leavers (100) / -0.029 / -0.025
(0.015) / (0.015)
Late leavers (110) / -0.025 / -0.019
(0.020) / (0.019)
Age / 0.000
(0.001)
Education / -0.002
(0.005)
Gender / 0.021
(0.011)
Income / -0.001
(0.000)
Occup. status: intermediate / -0.005
(0.012)
Occup. status: high / -0.019
(0.022)
Agreeableness / -0.005
(0.007)
Conscientiousness / -0.001
(0.006)
Extraversion / -0.016
(0.006)
Intellect / Openness / -0.016*
(0.006)
Neuroticism / -0.016*
(0.007)
Constant / -0.034** / -0.078*
(0.008) / (0.033)
Observations / 4232 / 4232

*p < 0.05, **p < 0.01.

a Control variables: personality (big 5), education, income, occupational status, gender, and age.