Innovation by firms and industries requires that the individual firm can combine internal and external knowledge resources. This paper studies product innovations as they are reflected by product varieties and destination markets, combined into observations of firms’ destination-specific varieties(variety pairs). The number of varieties (identified in this way) measuresthe extensive margin of exportflows from industries in local economies, reflecting past product and market (destination) innovations made by industries in each local economy. The empirical analysis identifies for each industry and local economy (i) the intra-industry knowledge resources, (ii) the local access to the supply knowledge-intensive producer services, and (iii) the access to the supply of knowledge-intensive producer servicesoutside the local economy. Thepapercontributes to existing knowledgein several ways. First, it introduces a knowledge-supply accessibility measure to model the local innovation milieu. Second, it shows the joint contribution to product innovation from internal and external knowledge sources. The estimation results supports the hypothesis that innovations are generated in the conjunction of internal and external knowledge.