Abstract
National policies designed to alter board gender composition have yielded mixed results globally. Social network analysis (SNA) of board interlocks using longitudinal data provides a robust tool for policymakers to evaluate the effectiveness of such policy changes. However, access to national longitudinal data including both listed and unlisted companies is rare. We utilise such data from the South African Companies and Intellectual Property Commission registry to describe how policy changes reconfigure network structures. We extracted data from listed and unlisted companies that have achieved a critical mass of three or more women directors yielding 17 486 company observations. Employing SNA, we differentiated between active firm interlocks and their evolution following four periods of policy change in South Africa. This study elucidates policy-induced structural shifts in the firm networks of women board members and offers discourse on the direction of future board gender diversity policy implementations in South Africa.