This article presents the results of a study measuring possible overblocking due to copyright moderation and changes in the diversity of cultural products supply on YouTube in two European Union (EU) member states comparable in size and population, Germany and France. Both have adopted Article 17 of the EU Copyright in the Digital Single Market (CDSM) Directive (CDSMD) but Germany was 5 months ahead of France in changing its legislative regime for large social media platforms and copyright content moderation. The article assesses how content takedowns that were likely connected to copyright differed in these two countries and how this might have been influenced by the greater copyright moderation linked to the implementation of Article 17 of the CDSMD. Furthermore, the cultural supply diversity according to genre on YouTube was examined by applying Stirling's model of diversity and using a dual-concept diversity index. To the best of the authors' knowledge, this is the first attempt to measure predicted changes to overblocking and possible changes in cultural diversity on YouTube's infrastructure since the new copyright rules came into force in the EU. The findings show that during the period examined, 2019–2022, significant differences were identified between Germany and France in terms of the takedowns of videos from categories prone to copyright moderation. In addition, the content-level supply of cultural products diversity, measured by genre (channel categories), number of videos, and subscribers, decreased in YouTube's available content in both countries but more so in Germany than in France. The study also makes a methodological contribution to the field of content moderation by reusing previously collected data to explore YouTube's infrastructure and cultural diversity within the framework of media economics. Platforms' content moderation practices and the potential impacts they have on cultural diversity are notoriously difficult to study, and this research establishes new methodological frameworks for further exploration.
