Research Policy 31 (2002) 509–526 Science dependence of technologies: evidence from inventions and their inventors Robert J.W. Tijssen Centre for Science and Technology Studies (CWTS), Leiden University, P.O. Box 9555, 2300 RB Leiden, The Netherlands Received 26 November 2000; received in revised form 14 December 2000; accepted 19 March 2001 Abstract Articulating a compelling economic rationale to justify investments in research—by definition furthest removed from direct, immediate economic benefit—is perhaps one of chief challenges of R&D managers, policy makers and science analysts in the years ahead. Although several innovation studies and surveys have provided some convincing empirical evidence of impacts and benefits of research to technical progress, there is still an urgent need for comprehensive models, reliable data and analytical tools to describe and monitor links between R&D and industrial innovation in more detail. As for the role of scientific and engineering research in the innovation process, this paper reports on the findings of a novel methodology to increase our understanding of the contribution of research efforts to successful technical inventions. The approach is based on a nation-wide mail survey amongst inventors working in the corporate sector and the public research sector in The Netherlands. The inventors’ inside information regarding their patented inventions—and related technological innovations on the market—provided a range of quantitative data on the importance of the underpinning research activities. Statistical models attempting to explain the degree of “science dependence” of the inventions identify a range of relevant variables, covering the inventor’s own capabilities and previous R&D achievements, external information sources, as well as the inventor’s R&D environment in general. Some 20% of the private sector innovations turned out to be (partially) based on public sector research. Furthermore, citations in patents referring to basic research literature were found to be invalid indictors of a technology’s science dependence. © 2002 Elsevier Science B.V. All rights reserved. Keywords: Science base of industrial innovation; Patents; Patent citations; Inventors 1. Introduction Newly emerging R&D-intensive industrial sec- tors will increasingly be built on a combination of leading-edge scientific knowledge and sophisticated technical know-how. The scientific and engineering research that we conduct today will have an impact on the economic success of corporations and countries in 5, 10, and even 15 years into the future. However, de- spite living in such an increasingly knowledge-based E-mail address: tijssen@cwts.leidenuniv.nl (R.J.W. Tijssen). society, the processes by which scientific and technical knowledge drive industrial competitiveness and eco- nomic impact remain one of the most difficult areas to assess and understand. Little is known about the quantitative impact of research activities and outputs on industrial innovations. This lack of detailed under- standing not only undermines the economic rationale for public and private investments in research—espe- cially the expenditure for risky exploratory academic research with long-term objectives and uncertain payoffs—but also the public confidence in the societal benefits and rates of returns of academic research. 0048-7333/02/$ – see front matter © 2002 Elsevier Science B.V. All rights reserved. PII:S0048-7333(01)00124-X