Seite - (000313) - in Knowledge and Networks

310 trusted, and less noisy knowledge exchanges. Second, at an aggregate level of anal- ysis such as the urban level, the control power that gatekeepers can exert on the knowledge flows they govern can more than offset the benefits accruing from their superior inventive performance. An excessive reliance upon indirect flows mediated by gatekeepers can signal a situation of knowledge dependence that is at higher risk of linkage disruption. Moreover, the intellectual expertise and skills necessary to act as effective gatekeepers are likely to be rather rare and possibly only present in large and technologically sophisticated organizations. Should one conclude from what our analysis that gatekeepers are not neces- sary—or even detrimental to the renewal of a city’s knowledge base? We believe that this conclusion is not warranted. In a companion article (Breschi & Lenzi, 2015), we show indeed that the role played by gatekeepers may indeed be impor- tant, but only in some specific circumstances. In particular, by confirming the long- standing intuition of Tushman and Katz (1980) and Tushman and Scanlan (1981), we show there that gatekeepers only play an important role when the knowledge base of a city is sufficiently different and specialized with respect to other cities to require the absorption of knowledge and the transcoding function of those actors. In conclusion, the chapter is intended to provide a contribution to the literature on both conceptual and methodological grounds. First, we clarify and qualify the role and function of gatekeepers. Second, we propose an operational method to quantify the importance of gatekeepers in brokering knowledge flows across cities and a set of new indicators that allow measurement of the meso-level effects (i.e., at the city level) of individual behavior and interactions (i.e., of inventors, gatekeepers, and co-invention networks). We hope that they will be useful and deployed in future research. References Agrawal, A., & Cockburn, I. (2003). The anchor tenant hypothesis: Exploring the role of large, local, R&D-intensive firms in regional innovation systems. International Journal of Industrial Organization, 21, 1227–1253. doi:10.1016/S0167-7187(03)00081-X Allen, T. J. (1977). Managing the Flow of Technology. Cambridge, MA: MIT Press. Bathelt, H., Malmberg, A., & Maskell, P. (2004). Clusters and knowledge: Local buzz, global pipelines and the process of knowledge creation. Progress in Human Geography, 28, 31–56. doi:10.1191/0309132504ph469oa Beaudry, C., & Schiffauerova, A. (2009). Who’s right, Marshall or Jacobs? The localization versus urbanization debate. Research Policy, 38, 318–337. doi:10.1016/j.respol.2008.11.010 Bettencourt, L. M. A., Lobo, J., & Strumsky, D. (2007). Invention in the city: Increasing returns to patenting as a scaling function of metropolitan size. Research Policy, 36, 107–120. doi:10.1016/j. respol.2006.09.026 Borgatti, S. P. (2006). Identifying sets of key players in a social network. Computational and Mathematical Organization Theory, 12, 21–34. doi:10.1007/s10588-006-7084-x S. Breschi and C. Lenzi