Answers are grounded in this paper and cite their sources.
We supplement the 'Idea Production Function' (IPF) with measures of R&D capital. We construct the R&D capital stock in the US, and estimate the IPF with patent applications as R&D output, allowing for a flexible treatment of R&D productivity (over 1968-2019).
No takes yet. Share an insight, caveat, or question.
Growiec et al. (2023) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: