Interlocking Directorates, Corporate Governance Networks, and Collective Action in Nigerian Business Groups

This dissertation investigates interlocking directorate networks among Nigerian business groups, examining how network structure shapes corporate governance quality and collective action dynamics. Interlocking directorates, where directors serve simultaneously on multiple company boards, create formal network ties that may facilitate information sharing, strategic coordination, and governance learning, but also raise concerns about conflict of interest, reduced board independence, and anti-competitive behaviour. In Nigeria, interlocking networks among business group affiliates represent a significant but under-researched governance phenomenon. Drawing on social network theory, corporate governance literature, and collective action theory, this study constructs a comprehensive directorate network map for one hundred and twenty listed firms using twenty years of annual report data, identifying network clusters, bridge directors, and governance contagion pathways. Governance outcomes measured include board independence quality, audit opinion types, earnings management levels, and regulatory compliance records. Network analysis techniques including centrality analysis, structural hole measurement, and community detection algorithms are applied. Econometric analysis using network-based instrumental variables addresses endogeneity in the network-governance relationship. The study makes original contributions through its construction of a longitudinal Nigerian directorate network dataset, its application of network analysis methodology to Nigerian governance research, and its theoretical integration of collective action dynamics into the governance network literature. Findings will assist regulators, institutional investors, and governance researchers in understanding network-level governance effects. Keywords: interlocking directorates, governance networks, corporate governance, business groups, social network analysis.