Thanks to Wally Clausen for pointing me to a recent article in the online journal Working Knowledge published by Harvard Business School. Sara Grant interviews HBS associate professor Lee Fleming about his research on inter-organizational networks of inventors.
It's a good article, especially if you're interested in collaborative innovation, and even more so if you're interested in Boston, where Fleming has conducted his network surveys. You can read the article here: "Caves, Clusters, and Weak Ties: The Six Degrees World of Inventors."
Fleming has studied networks of inventors by cataloging jointly filed patents. He's found that by the mid-90's most of Boston's inventors were at least indirectly connected by these jointly-filed-patent relationships.
To put a more intuitive spin on this result, it's similar in spirit to a Swedish study showing that virtually all adult Swedes are connected in a giant "slept with" network. Of course, the Swedish researchers did not have legal papers documenting each link in this sexual network, but ultimately they were driven by a similar quest to understand large-scale connectivity.
Fleming concludes with thoughts on how managers can use inventor networks to their advantage: "Simple awareness of the shrinking world of inventors is the first step. Set up unobtrusive legal protection, make your technical professionals aware of the issues, and then trust them to manage their knowledge sharing."