This paper uses panel regression techniques to assess the policy determinants of private sector innovative activity – proxied by R&D expenditure and the number of new patents – across 19 OECD countries. The relationship between innovation indicators and multifactor productivity (MFP) growth is also examined with a particular focus on the role of public policies in influencing the returns to new knowledge. The results establish an empirical link between R&D and patenting, as well as between these measures of innovation intensity and MFP growth. Innovation-specific policies such as R&D tax incentives, direct government support and patent rights are found to be successful in encouraging the innovative activities associated with higher productivity growth. However, direct empirical evidence of the positive effects of these policies on productivity is less forthcoming. A pervasive theme from the analysis is the importance of coupling policies aimed at encouraging innovation or technological adoption with well designed framework policies that allow knowledge spillovers to proliferate. In particular, the settings of framework policies relating to product market regulation, openness to trade and debtor protection in bankruptcy provisions are found to be important for the diffusion of new technologies.