Evidence for Science Policy: What Can Public Research Do for Innovation and Growth?

Large-scale research and technology infrastructure investment decisions should be evidence-informed, yet the long-term, economy-wide effects of these investments remain difficult to establish. The evaluation literature has identified the constraints: attribution is hard, comparison groups are rarely available, and the interval between investment and measurable effect often exceeds the evaluation window. What has been missing is not recognition of these problems but settings in which they can be overcome. This contribution brings together two academic studies—one macroeconomic, one microeconomic—in which the historical variation setting permits credible causal estimates of the returns to public research. Neither settles the general question of what public research returns; each shows what becomes measurable when the identification problem is solved, and in both cases, what becomes visible complicates a prevailing assumption, demonstrating the value in complementing policy-led evaluations with those from academia. Four policy implications follow: (i) economic effects depend on the type of knowledge produced, the composition of expenditure, and the industrial context, so evidence from one programme may not transfer to another; (ii) where mission-oriented investment is expected to generate wider economic spillovers, that expectation should be evidenced rather than assumed; (iii) in the case examined here, the spillovers that justify public investment were weaker for applied, mission-directed research than the basic-research rationale would predict; and (iv) the value of research infrastructure includes not only financial cost but the time and knowledge embodied in tools and equipment.