In the section General difference in affiliations and journals of this appendix, we identify what are the most American/European topics resulting from our topic model approach. To achieve our goal, we computed how much each topics is characterize by particular publications venues (EER vs. Top 5), and by the countries of affiliations of the authors (the US vs. European countries).
In the section Details on the different topics of this appendix, users can explore information about the individual topics. We produced a variety of tables to explore the most cited references of the topics, or the most common terms of the topics. In addition, users can also find some intra-topics information about how the topics evolved in importance overtime, or the differences in the clusters between European/American authors and/or venues of publications.
Articles have multiple topics, and more importantly, articles have different ‘rate of belonging’ for each of their topic (the gamma value). We are able, for each topic, to compute the difference in the means of gamma values for (i) articles published in the EER and articles published in the Top 5 and (ii) articles written by US-based authors and those written by European-based authors.
If we look at the distribution of topics by gamma mean depending on affiliations and journals: