A shot in the dark? Policy influence on cluster networks

•Impact of innovation-oriented cluster policy (BioRegio) on knowledge networks.•BioRegio had significant effects on innovation output but weak effects on local network structures.•Overall, weak evidence of long run effects of BioRegio on network structures.•Subsidies for joint R&D with greater impact on network cohesion than BioRegio.•BioRegio and subsidies for joint R&D are substitutes rather than complements.