The formation of R&D cooperation ties: an event history analysis for German laser source manufacturers
研究了德国激光源制造商在1990-2010年间进入研发网络并建立合作的时间规律，发现公共研究机构的衍生企业更易启动首次合作，网络位置有利于后续合作，而空间邻近性效果不一。
This study sheds light on a phenomenon that has remained widely neglected in the literature on innovation networks so far: the timing of network entries and consecutive research and development (R&D) cooperation events. We employ an event history approach based on a unique industry data set that encompasses the entire population of laser source manufacturers in Germany between 1990 and 2010. Quarterly network layers are constructed from databases on publicly cofunded R&D cooperation projects. We find that spin-offs from public research organizations have a considerably high propensity to initiate a first cooperation. A strategic position within the R&D network is conducive to the establishment of further R&D linkages. Spatial proximity (or colocation in a regional industry cluster) produces mixed results.