Online Appendix. Robustness checks and additional analyses

Table 1: Covariate balance of all items in the family activity index and cultural activities index as well as the indices for total cognitive ability at age 5 and 10.

Unmatched baseline / Matched ATT 1:1
p-value / KS p-value / p-value / KS p-value
Cultural activities 1:
Reading books / .000 / .000 / .807 / 1
Cultural activities 2:
Goes to a club or organization / .000 / .000 / .611 / .998
Cultural activities 3:
Goes to museums / .000 / .000 / .735 / 1
Cultural activities 4:
Goes to libraries / .000 / .000 / .328 / .909
Cultural activities 5:
Plays a musical instrument / .000 / .000 / .081 / .158
Family activities 1:
Go for walks / .000 / .010 / .220 / .408
Family activities 2:
Goes to outings together / .000 / .014 / .127 / .408
Family activities 3:
Go to holidays together / .000 / .000 / .667 / 1
Family activities 4:
Go shopping together / .732 / 1 / .244 / .451
Family activities 5:
Chat for at least five minutes / .000 / .205 / .849 / 1
Family activities 6:
Go to a restaurant together / .047 / .146 / .019 / .329
Cognitive ability, age 5 / .000 / .000 / .893 / .496
Cognitive ability, age 10 / .000 / .000 / .480 / .367

Figure 1: Standardized bias in the unmatched sample (left) and the matched sample (right). Bias for all items in the family activity index and cultural activities index as well as the indices for total cognitive ability at age 5 and 10.

Table 2: Robustness checks of the effects of higher education on political participation. Genetic matching (1:2) with replacement.

1:2
Estimate / p-value
Voted in 2001 election / .034 / .216
Demonstration / .010 / .546
Signed a petition / .023 / .473
Contacted MP / .013 / .486
Attended public meeting or rally / .024 / .192

Table 3. Robustness checks of the effects of higher education on political participation. Genetic matching (1:1, 1:2) without replacement.

1:1 / 1:2
Estimate / p-value / Estimate / p-value
Voted in 2001 election / .072 / .006 / .108 / .000
Demonstration / .009 / .427 / .017 / .054
Signed a petition / .051 / .055 / .055 / .016
Contacted MP / .012 / .397 / .026 / .022
Meeting/rally / .023 / .092 / .026 / .018

Table 4: Robustness check: matching on an imputed data set. Genetic matching (1:1) with replacement.

Imputed dataset
Estimate / p-value
Voted in 2001 election / .039 / .053
Demonstration / .001 / .947
Signed a petition / .015 / .525
Contacted MP / .016 / .151
Attended public meeting or rally / .017 / .199