Have research and development spillovers declined in recent decades?
Core argument: R&D spillovers remained stable from 1980 through the 2010s, generating about $4 of social benefit per $1 of R&D spent, contrary to concerns that spillovers have declined in the 21st century.
Despite concerns about declining R&D spillovers, data from 1980 through the 2010s indicate stability, with $4 of social benefit for every $1 of R&D spent. Notably, spillovers peaked between 1997-2001, coinciding with the dot-com boom, reflecting market enthusiasm for R&D-intensive firms. The study highlights large positive spillovers among technologically close firms and negative effects from product market rivals due to business-stealing. While R&D tax credits effectively boost firm-level R&D spending, their impact on R&D volume may be limited if the supply of researchers is inelastic. This suggests policies should focus on increasing the quantity and quality of potential inventors, such as through STEM education and broadening access for underrepresented groups.



