摘要：The commercial value of basic knowledge depends on the arrival of follow-up
developments mostly from outside the boundaries of the inventing firm. Private
returns would depend on the extent the inventing firm internalizes these
follow-up developments. Such internalization is less likely to occur as
knowledge becomes more general. This motivates the historical concern of
insufficient private incentive for basic research. The present paper develops a
novel empirical methodology of identifying unique patterns of knowledge flows
(based on patent citations), which provide information about whether ‘spilled’
knowledge is reabsorbed by its inventor. Using comprehensive data on the largest
500 inventing firms in the US the classical problem of underinvestment in basic
research is confirmed: spillovers of more general knowledge (and in this
respect, more basic) are less likely to feed back to the inventing firm. This
translates to lower private returns, as indicated by the effect of the R&D
stock of the firm on its market value.
关键词：basic knowledge, spillovers, patents and citations
