This paper examines whether there are spillover effects from public intangibles like research and development (R&D) to private sector productivity. The authors constructed a new dataset covering 12 countries, 20 industries, and 4 time periods to analyze the relationship between non-market R&D spending and market sector productivity growth. Statistical analysis found a positive correlation, with countries that had higher lagged non-market R&D exhibiting higher subsequent market sector productivity growth. Regression results also suggested spillover effects from non-market R&D to market productivity, with estimated rates of return on public R&D found to be very high. The findings provide evidence that public investment in intangibles like R&D can boost private sector