Silicon Valley has been the envy of local governments and business developers, but most of their attempts to clone the high-tech hotbed have been only marginally successful. The unique feature other regions have failed to replicate is an infrastructure expert at facilitating start-ups, according to a University of California, Davis, professor who has edited a new book on Silicon Valley. In "Understanding Silicon Valley," Martin Kenney and co-author Urs von Burg, a former UC Davis researcher, argue that this complex is the trait that sets Silicon Valley apart from most other industrial clusters. The critical feature in the dynamism of Silicon Valley is "the institutional complex specialized at creating new firms aimed at exploiting fast-moving technological trajectories," they write in the closing essay. The 285-page book, published by Stanford University Press, features nine essays by leading analysts of the region in five academic disciplines: business studies, geography, history, regional planning and sociology. Von Burg and Kenney, a professor of human and community development and a senior research associate at the Berkeley Roundtable on the International Economy, write that Silicon Valley consists of two intertwined economies. One consists of established firms, corporate research laboratories and universities and the other, of law firms, investment banks, executive search firms and marketing organizations, for example. After frequently dealing with the same issues, local organizations evolved knowledge and expertise suited to the unique needs of high-tech start-ups and so contributed to the acceleration of the start-up process and the success of the new firms, the authors say. Kenney and von Burg are "pessimistic" about policies aimed at cloning Silicon Valley, but suggest that a proliferation of start-up opportunities may allow local firms in other regions to gain expertise and to develop this second economy. EDITOR'S NOTE: For a review copy, please contact Lorraine Weston of Stanford University Press by phone (650) 736-0925, fax (650) 736-1784 or e-mail lweston@stanford.edu.