Papers I’m aware of that compare different Wikipedias. Do you know of other investigations comparing Wikipedias?
“Cultural Differences in Collaborative Authoring of Wikipedia”  compared French, German, Japanese and Duch Wikipedia. They used content analysis methods on just the page “Game” from the different Wikipedias, i.e just 4 pages. Authors find some correlations between patterns of contributions (number of deleting actions, of adding actions, of corrective actions) and the four dimensions of cultural influences proposed by Hofstede (Power Distance, Collectivism versus Individualism, Femininity versus Masculinity, and Uncertainty Avoidance). They conclude thatcultural differences that are observed in the physical world also exist in the virtual world.
“Cross-cultural analysis of the Wikipedia community”  analyzed English, Hebrew, Japanese, and Malay. They used content analysis of 120 Wikipedia talk pages (randomly sampled among “user talk pages”, “article talk pages”, and “Wikipedia policies talk pages”) in 4 language Wikipedias that differ in size and culture: English (western, big), Hebrew (western, small), Japanese (eastern, big) and Malay (eastern, small). Authors find that “Courtesy” postings were more frequent in large than in small Wikipedias, and in Eastern than in Western (significant). This is probably connected to Hofstede’s high vs low power distance, because high politeness is associated with high power distance. Plus, in collectivistics/high power distance cultures relationships prevail over tasks. Other correlations were not significant.
“Issues of cross-contextual information quality evaluation — The case of Arabic, English, and Korean Wikipedia”  compared Arabic, English, and Korean Wikipedias. Authors used many different methods, including content analysis of featured articles and count of number of Internal Links, of edits, of Adjacent Pages, of Registered Users, … and applied multivariate statistical analysis in order to find correlations. Hofstede’s cultural dimension scores for the United States, South Korea and the Arab World were also used to assess pair-wise similarity of the Wikipedias at the cultural level. They conclude that different Wikipedia communities may have different models for quality.
“Conflictual Consensus in the Chinese Version of Wikipedia”  focuses on one single Wikipedia, the Chinese one, and compares point of regional differences of its contributors based on four regions of origin (Mainland, Hong Kong / Macau, Taiwan, and Singapore / Malaysia). Authors claim that the main issue threatening the potential growth of Chinese Wikipedia are not the internal conflicts, nor the external competition by Baidu Baike but the evolution of the newly established “Avoid Region-Centric Policy”.
“Analyzing Cultural Differences in Collaborative Innovation Networks by Analyzing Editing Behavior in Different-Language Wikipedias”  does not use manual content analysis but social network analysis as a lens for comparing English, German, Japanese, Korean, and Finish language Wikipedias finding a difference between egalitarian cultures such as the Finnish, and quite hierarchical ones such as the Japanese.
 Pfeil, U., Zaphiris, P. and Ang, C. S. 2006. Cultural Differences in Collaborative Authoring of Wikipedia. Journal of Computer-Mediated Communication, 12, 88–113.
 Hara, N., Shachaf, P., & Hew, K.F. 2010. Cross-cultural analysis of the Wikipedia community. Journal of the American Society for Information Science and Technology, 61(10), 2097–2108.
 Stvilia, B., Al-Faraj, A., & Yi, Y. 2009. Issues of cross- contextual information quality evaluation—The case of Arabic, English, and Korean Wikipedias. Library & Information Science Research, 31(4), 232-239.
 Liao, H. 2009. Conflictual Consensus in the Chinese Version of Wikipedia. IEEE Technology and Society Magazine.
 Nemoto, K. Gloor, P. 2010. Analyzing Cultural Differences in Collaborative Innovation Networks by Analyzing Editing Behavior in Different-Language Wikipedias. Proceedings of COINs 2010, Collaborative Innovations Networks Conference, Savannah GA, Oct 7-9, 2010