Figures compiled in the study show that metro areas now generate more than 80 percent of the nation's employment, income and production of goods and services. As such, public and private-sector investment aimed at promoting national economic growth should focus on metro areas, the report argues, since these contain the bulk of the nation's productive assets. In terms of metro economies, Silicon Valley, San Jose and San Francisco are shining examples of the way economic growth and prosperity is now tied to industry clusters within a region. Clustering businesses and households in metropolitan areas reduces the operating cost of warehousing, transportation, communications and utilities. Perhaps even more important than clustering in a knowledge economy, knowledge-sharing is most prevalent in metro areas.
Ideas diffuse rapidly between firms that are in close proximity to each other.
And such knowledge and technology transfers between companies frequently result in increased innovation. Moreover, metro areas tend to have direct access to export markets. Most regional and international exports travel through metro areas on the way to their final destination. So companies in metro areas have more access to these export markets, as well as large internal markets. And metro areas tend to provide the economic, institutional, legal and social infrastructure that firms and industries need.