Key points are not available for this paper at this time.
Walter W. Powell, Kenneth W. Koput, Laurel Smith-Doerr, Interorganizational Collaboration and the Locus of Innovation: Networks of Learning in Biotechnology, Administrative Science Quarterly, Vol. 41, No. 1 (Mar., 1996), pp. 116-145
Powell et al. (Fri,) studied this question.