Socio-spatial relations observed in the global city network of firms

Worldwide connections of influencers who promote e-cigarettes on Instagram and TikTok: a social network analysis

Exposure to e-cigarette marketing on social media is a risk factor for e-cigarette use among youth. Tobacco brands use influencers to promote e-cigarettes on social media; however, influencer marketing has not been sufficiently studied. This study explored network connections and interactions through comments on social media posts between global nano- and micro-influencers (influencers with approximately 1,000 to 100,000 followers) and their audiences on Instagram and TikTok. We constructed directed unipartite networks among Instagram (N = 104) and TikTok (N = 100) influencers and users on Instagram (N = 55,622) and TikTok (N = 68,673) who commented on these influencers' posts in 2021-2022 (including influencers who commented on each other's posts). Comments to posts of users who were not classified as influencers were not collected. The Instagram network was denser (more interconnected) and active compared to the TikTok network (1.48 times higher density, 281 times higher transitivity, and 85 times higher reciprocity). Both Instagram and TikTok networks contained heterophilic ties (i.e., influencers from different geographic regions such as Asia, North America and Europe connected to each other), indicating that influencers from different geographic regions engage with (comment on) each other's content, potentially exposing audiences to a wide variety of e-cigarette content. Influencers who promote e-cigarettes and post about lifestyle topics (e.g., fitness, fashion, gaming) occupy more central positions in the Instagram and TikTok networks than influencers who focus primarily on e-cigarette promotion, potentially exposing users who are not interested in tobacco-related content to harmful imagery of e-cigarettes. The findings emphasize the need for strengthening influencer marketing regulation on social media platforms popular among youth.

Gender Identity and Student Perceptions of Peer Research Aptitude in CUREs and Traditional Laboratory Courses in the Biological Sciences

While several studies have investigated gender inequities in the social learning environment of biology lecture courses, that same phenomenon remains largely unexplored in biology laboratory contexts. We conducted a mixed methods study to understand the influence of gender on student perceptions of their peers' research aptitude in introductory biology CUREs and traditional laboratory courses. Specifically, students (N = 125) were asked to complete a name generator survey at three time points across the semester. This survey asked students to list the names of peers whom they viewed as "most proficient" in the course investigations and to justify their choice via an open-ended response prompt. Using social network analysis, exponential random graph modeling (ERGM), and thematic analysis, we demonstrate that student gender identity did not influence nomination behaviors in CURE or traditional laboratory courses. However, the ERGMs reveal the presence of a popularity effect in CUREs and demonstrate that mutual nominations were more prevalent in traditional laboratory courses. Our qualitative data further provide insights into the reasons students nominated peers as proficient in CURE and traditional courses.

Firm Heterogeneities, Multi-Dimensional Proximities, and Systematic Dynamics of M&A Partnering: Evidences from Transitional China

Corporate investment strategies and decision-making processes are crucial for understanding the operation and evolution of socioeconomic systems. Mergers and acquisitions (M&As) have been the main mode of corporate investment, growth, and upgrading, deeply affecting corporate reorganization, regional industrial restructuring, and economic globalization. By building a database including 5543 M&A partnerings and 1.89 million M&A non-partnerings, this study aims to uncover the systematic dynamics of M&A partnering in regional China during different phases since the mid-1990s, with particular attention given to the effects of firm heterogeneities and multi-dimensional proximities. Although geographical, cognitive, organizational, and institutional proximity dimensions are significantly influential for M&A partnering, we find that the effects of multi-dimensional proximities differ across M&A types and involving firms. Specifically, organizational proximity matters more for large- and medium-sized acquirers, while institutional proximity plays a more vital role in the acquisition target selection of private-owned and small-sized acquirers. Cognitive proximity measured by industrial and technical relatedness is more crucial for horizontal, vertical, and conglomerate M&As that are tightly associated with the corporate product, technical, and functional upgrading. The results indicate that the benefits of cognitive proximity may offset the risks and costs resulting from long-distance M&As, demonstrating the interactive dynamics between proximity dimensions. Our findings suggest that firm heterogeneities, proximity dynamics, and contextual factors should be focused on when explaining the investment decision-making processes of individual corporations in emerging and transitional economies such as China.