Mobility of Innovators and Prosperity of Geographical Technology Clusters: A longitudinal examination of innovator networks in telecommunications industry

Although knowledge spillovers have long been considered a critical element for development of technology clusters by facilitating innovations, the relationship between characteristics of knowledge spillover network and regional cluster’s growth is ambiguous. Based on patent co-authorship data, we construct inventor networks for two geographical telecom clusters – New Jersey and Texas – and investigate how the networks evolved longitudinally as the technology clusters were undergoing different stages of their lifecycles. The telecom industry in the former state had encountered a significant unfavorable environmental change, which was largely due to the breakup of the Bell System and evolution of the telecom industry. Meanwhile, the telecom cluster of Texas has been demonstrating a growing trend in terms of innovation output and is gradually replacing New Jersey’s leadership in telecom innovation as measured by number of patents per year. We examine differences and similarities in dynamics of the innovator networks for the two geographical clusters over different time periods. The results show that TX’s innovator networks became significantly better connected and less centralized than the ones of NJ in the later years of the time series while the two clusters were experiencing different stages of lifecycle. By using network visualization tools, we find the overwhelming power of Bell System’s entities in maintaining the NJ innovator network to be lasting a very long time after the breakup of the company. In contrast the central hubs of TX’s networks are much less important in maintaining the networks.