The indicators reflect this definition of Silicon Valley, except where noted as different. The 35 indicators that follow were chosen in consultation with the Index Advisory Board, the Joint Venture Board, and more than 60 community experts. Appendix A provides detail on data sources for each indicator. An industry cluster is a geographic concentration of interdependent firms in related industries, and includes a significant number of companies that sell their products and services outside the region. Healthy, outward-oriented industry clusters are a critical prerequisite for a healthy economy.
Clusters are dynamic.
Over time, existing clusters will transform and new clusters will develop from our region's talent and technology base. The Internet cluster is a good example. In July 1999, Joint Venture released an analysis of the emerging Internet cluster in Silicon Valley . Although it is possible to identify local companies with Internet-related activities, government statistics do not yet track employment in these companies as a separate sector. The widespread adoption of a new federal industry classification scheme, the North American Industry Classification System, over the next few years should improve our ability to track Internet-related companies as a sector.