Abstract
Two ideas have emerged as central in evolutionary economic geography in recent years: First, innovation is often the result of meetings between related ideas, and regions are therefore best served by hosting a variety of related industries. Second, innovation often comes from the combination of different knowledge bases. However, there have been few attempts at linking these approaches in empirical studies. This paper connects the dots by examining relatedness among industries with similar and different knowledge bases in specific regional contexts. We focus on regions expected to have different types of innovation systems, from the organisationally thick and diversified RIS of large cities through the more specialised RIS in intermediate cities to the organisationally thin RIS found in small rural regions. The analysis finds that industries with different knowledge bases are related in various regional settings, with combinatorial knowledge base industries having a central role in many regions. However, there are also cases of potential lock-in, where relatedness is mainly found among regions with the same knowledge base.