Giant cluster formation and integrating role of bridges in social diffusion

Chang, S, Lee, J and Song, J (2023) Giant cluster formation and integrating role of bridges in social diffusion. Strategic Management Journal, 44 (12). pp. 2950-2985. ISSN 0143-2095

Abstract

Social networks often exhibit the aggregation of isolated subgroups into a massively connected subgroup, when individuals keep building bridges across subgroups. To understand the roles of bridges in integrating subgroups, we develop models focusing on the percentage of bridges in the system. When the percentage of bridges from all ties is strictly below 1%, diffusion does not affect many individuals because the system is merely a collection of fragmented subgroups. Near 1%, however, we find that a tiny percentage increase in bridges leads to sudden widespread diffusion across many subgroups. This dramatic change stems from the threshold-like structural characteristic—previously fragmented subgroups come together abruptly. Our findings suggest that this integrating role of bridges is an important missing piece in the literature on small-world networks.