Table 4.

Relevant contemporary thematic clusters

Cluster	Number of items	Key contribution in the cluster	Topic
1	19	Helbling et al. (2017)	Migration policies
2	16	Kaunert (2009)	Education policies
3	16	Schneider (2009)	Comparative politics, metrics and scientometrics
4	16	Bühlmann et al. (2012)	Democracy and governance