1 Pre-Print version: Mobile Media & Communication The convergence of mobile and social media: Affordances and constraints of mobile networked communication for health workers in low- and middle-income countries Christoph Pimmer and Kate Tulenko Abstract The increasing convergence of mobile and social media is highly transformational because it is shifting the dominant form of digital communication from bilateral towards mobile and networked communication among distributed interactants. This paper explores the affordances and constraints of this dynamic for global health in low and middle income countries (LMICs). In these settings, research and practice have focused on one- or two-way communication designs and on approaches that position health workers as passive actors. To extend current views, three domains of mobile social media usage are theorized: (1) socio-cognitive learning; (2) Socio-cultural professional participation; and (3) Concertive peer and multi-stakeholder control. The theoretical discussion is illustrated with empirical examples from a non-systematic literature review to account for the wide and interdisciplinary problem space. In the second part of this analysis, suggestions are discussed regarding how to anchor and facilitate mobile social media spaces within existing institutional structures. Finally, this paper argues that leveraging the affordances of mobile social-media-based communication requires the consideration of several constraints and challenges, including the economics of participation, privacy and surveillance, regulation and information quality, equal socio-cultural participation and technical competencies and professionalism. Keywords: mobile phone; mobile communication; social media; social networks; LMIC; health; m- health