This study analyses the effectiveness of targeted public support for R&D investment. In particular, we test whether the specific policy design aiming at incentivizing (international) collaboration and R&D in small and mediumsized firms achieves the desired objectives on input as well as output additionality. Our results show that the targeted R&D subsidies accelerate R&D spending in the private sector, and especially so in the targeted groups. Further, we differentiate between privately financed R&D and subsidyinduced R&D investment to evaluate their respective effects on innovation performance. The results confirm that the induced R&D is productive as it translates into marketable product innovations. While both types of R&D investments trigger significant output effects, we find that the effect of subsidy-induced R&D investment is higher for firms that collaborate internationally as well as for SMEs.