@techreport{NBERw16188,
 title = "Spillovers in Space: Does Geography Matter?",
 author = "Sergey Lychagin and Joris Pinkse and Margaret E. Slade and John Van Reenen",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "16188",
 year = "2010",
 month = "July",
 URL = "http://www.nber.org/papers/w16188",
 abstract = {We simultaneously assess the contributions to productivity of three sources of research and development spillovers: geographic, technology and product–market proximity. To do this, we construct a new measure of geographic proximity that is based on the distribution of a firm’s inventor locations rather than its headquarters, and we report both parametric and semiparametric estimates of our geographic– distance functions. We find that: i) Geographic space matters even after conditioning on horizontal and technological spillovers; ii) Technological proximity matters; iii) Product–market proximity is less important; iv) Locations of researchers are more important than headquarters but both have explanatory power; and v) Geographic markets are very local.},
}