Mobility and Social Networks: Localized Knowledge Spillovers Revisited

The paper provides a reassessment of arguments and tests in support of the existence and magnitude of localized knowledge spillovers. The authors use information in patents to control the mobility of inventors across companies and space, as well as for the network ties that such mobility helps establishing. The results indicate that localization effects tend to vanish where citing and cited patents are not linked to each other by any network relationship.