This paper uses a gravity framework to investigate the effects of distance as well as subnational and national borders in knowledge spillovers. Drawing on the NBER Patent Citations Database, we examine patent citations data at metropolitan level within the U.S. and the 38 largest patent-cited...

Foreign direct investment (FDI) in services has grown significantly in recent years. Evidence of spatial relationships in FDI decisions have been provided for goods manufacturing by utilizing physical distance-based measures of trade costs. This paper investigates spatial interactions for...