Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Data for all producers of automobiles and integrated circuits on their origins, base location, and performance are used to analyze the factors behind the historical clustering of the two industries in Detroit and Silicon Valley, respectively. Key ideas concerning organizational reproduction and heredity are elaborated and used to explain how spinoffs from incumbent firms in the same industry can lead to clustering. Findings concerning the spawning of spinoffs, entry by firms in related industries, and firm performance suggest that organizational reproduction and heredity were the primary forces underlying the clustering of the two industries.