The dynamics of criminal collaboration: Multiplex ties in mafia networks

This study examines how social embeddedness and multiplex relationships shape criminal collaboration within organized crime networks. Drawing on data from three major investigations into the 'Ndrangheta, we analyze how kinship, clan affiliation, leadership, and prior interactions influence participation in meetings and phone calls. Using relational hyperevent models, we assess the dynamic and multiplex nature of these networks across time and investigations. Results show that kinship, leadership, and shared clan affiliation consistently increase the likelihood of interaction, with stronger effects for face-to-face meetings. Prior joint interactions also predict future collaboration, especially when the mode remains consistent. We find contrasting patterns of closure: meetings resist triadic closure, reinforcing exclusivity and hierarchy, whereas phone calls promote connectivity by bridging structural holes. By modeling multiple relational mechanisms simultaneously and across different networks, this study contributes to research on criminal embeddedness and the structural organization of illicit collaboration.