Defensive, reactive, or proactive? A critical review and conceptual framework of the role of incumbent firms in sustainability transitions

This research addresses the literature on incumbent firms in sustainability transitions and makes two main contributions. First, it critically identifies and synthesises the diverse roles of incumbent firms: as defensive actors who resist change, reactive actors who respond to destabilising conditions, and proactive actors who have a stake in the change. It elaborates on each of these roles, their conceptual approaches, transition pathways, and the implications for ongoing research on incumbent firms. Second, based on this review, it introduces a conceptual model of an incumbent firm's dynamic and iterative interaction with sustainability transitions, arguing for the role of time and temporal dynamics in addition to the readiness of a firm's internal and external environments. This conceptual model introduces an incumbent firm's perspective on sustainability transitions and thus bridges the gap between the firm (micro level) and the socio-technical system (macro level) in the emerging research. • Incumbent firms adopt defensive, reactive, or proactive roles in sustainability transitions. • These roles imply different conceptual approaches, transitions pathways and implications for research. • The research offers a conceptual framework of the dynamic interaction of an incumbent firm with sustainability transitions. • The research adopts an incumbent firm’s perspective to sustainability transitions.