How many people in the world do research and development?

The traditional approach to comparing research and development (R&D) capacity across countries has been to compare Gross Domestic R&D expenditures (GERD). In this paper, we argue for an expansion of R&D capacity that includes people engaged in research and research and development activities (research human capital density, RHCD). To achieve this goal, we first discuss how to estimate counts of researchers and create a measure of researcher human capital density within a country. Next, we examine whether RHCD is a useful variable in models of innovation capacity. Finally, we consider whether RHCD has explanatory power for models of research outputs including patents and publications. We find that RHCD has more explanatory power than GERD in the production of patents and publications. We argue that surveys of individuals that include questions on R&D activities are useful for assessing innovation capacity, and, if adopted more broadly, can provide a strategic framework for countries and regions to develop human capital to support innovative activities.