Dynamics of Opinion Formation and Influence in Networked Communities: How Reddit Users Shape Urban Air Pollution

• In Event: 50620 - Section on Environmental Sociology Roundtables
  In Refereed Roundtable (60 minute): Table 16: Information Technology and the Environment

Abstract

Discussions about urban air pollution increasingly take place in online environments, where digital platforms facilitate public engagement with environmental risks. On Reddit, a semi-anonymous and decentralized platform, discussions about air quality emerge through user-generated content rather than institutional narratives, allowing diverse voices to shape public discourse. Unlike traditional media, where expert commentary and journalistic framing dominate, Reddit enables users to negotiate meanings, exchange information, and collectively interpret environmental issues in real-time. Within these discussions, certain individuals gain visibility and influence over how topics are framed, expanded, or contested. However, the mechanisms by which influence operates in these networked interactions—whether through content contributions, network positioning, or temporal engagement—remain unclear. This study examines the process of opinion formation on Reddit and the role of different types of users in shaping discussions about urban air pollution. This study considered influence as a continuum of engagement and network positioning rather than as a fixed “Opinion Leader” category. Through an integrated approach that combines dynamic topic modeling and social network analysis, this research addresses two central questions: This study asks: (1) How do thematic discussions on urban air pollution emerge and evolve in Reddit communities? (2) How does influence manifest in these discussions, and what network structures enable certain users to shape discourse more than others? By integrating topic modeling with SNA, this research explores whether influence emerges from structurally central users or develops through engagement strategies over time. The findings challenges assumptions that influence online discussions as a static property of prominent users. Instead, influence emerges through strategic engagement in early discourse phases. The distinction between early adopters and early majority users highlights different pathways to shaping public opinion: initiators versus reinforcers. Furthermore, the role of hubs as amplifiers rather than originators suggests that centrality metrics alone do not capture the full dynamics of online influence.

Author

• Yuhou Chen, McGill University