What drives start-up growth in innovation hubs? Microfoundational pathways and sociomaterial–institutional mechanisms

Purpose Innovation hubs play an increasing role in supporting entrepreneurship in emerging economies, yet the microlevel processes through which hub-based support enhances start-up growth remain unclear. This study adopts a microfoundational perspective, supplemented by sociomaterial and assemblage insights, to examine how mentorship, support facilities and institutional constraints shape the individual actions that generate network ties and influence growth. Design/methodology/approach Using survey data from 622 start-ups in Ghanaian innovation hubs and partial least squares structural equation modeling, the study analyses how developmental interactions and the use of material infrastructures give rise to network ties, and how these ties mediate the effects of hub-based support on growth under varying institutional constraints. Findings Mentorship and support facilities influence growth primarily through the network ties founders develop. Institutional constraints weaken the relational impact of mentorship but strengthen the networking value of support facilities, highlighting the sensitivity of microlevel behaviors to the institutional environment. Practical implications The study offers actionable insights for practitioners by showing that mentorship and support facilities improve entrepreneurial performance only when embedded in relational, interaction-rich hub environments. The findings highlight the need for hub managers to invest in relational infrastructure, for policymakers to strengthen hubs as stabilizing institutional anchors, and for development agencies to adopt integrated, system-oriented ecosystem interventions. Originality/value The study advances microfoundational perspective by showing how individual actions produce relational and sociomaterial coherence in fragile institutional contexts. It also demonstrates that institutional constraints actively shape how founders convert hub-based support into network relationships, highlighting the importance of relational infrastructures in hub design and policy.