Does the composition of regional knowledge bases influence extra-regional collaboration for innovation?

There is a growing research interest in the relationship between the composition of regional knowledge bases and the extra-regional collaborative ties maintained by actors during their development work. To investigate this relationship, we use patent data to characterize European NUTS 3 regions by their (i) comparative technological specializations; and (ii) related technological variety. We find domestic, extra-regional collaboration to be negatively associated with regional technological specialization and related technological variety. At the same time, we find related technological variety to serve in support of international innovation collaboration.