NBER Publications by Arvids Ziedonis

The growth of high-technology clusters in the United States suggests the presence of strong regional agglomeration effects that reflect proximity to universities or other research institutions. Using data on licensed patents from the University of California, Stanford University, and Columbia University, this paper compares the geographic 'reach' of knowledge flows from university inventions through two important channels: non-market 'spillovers' exemplified by patent citations and market contracts (licenses). We find that knowledge flows through market transactions to be more geographically localized than those operating through non-market 'spillovers.' Moreover, the differential effects of distance on licenses and citations are most pronounced for exclusively licensed university paten...