The second case study has been conducted in the San Francisco Bay Area in Northern California, particularly in the East Bay Area and in the Central Valley. The San Francisco Bay Area represents one of the most dynamically growing regions of the U.S. Particularly after World War II, the Bay Area has undergone a significant transformation in the context of urbanization and industrialization with the emergence of the high technology-district in the so-called Silicon Valley in Santa Clara County, the southern area of the region as one of the most important developments. As the S.F.-Oakland-San Jose Metropolitan Area, it represents the fifth largest metro area of the U.S. with a size of almost 18,000 square kilometres and a population of almost 7 million by July 2006 and 3.4 million employees by May 2007 (data after U.S. Census Bureau 2007, California Employment Development Department 2007) (see Map 5.1).