The U.S. Small Business Administration has helped form more than 40 industry clusters since 2009, fostering new regional activity and competitive centers for entrepreneurial growth. The SBA's Karen G. Mills explains how they got started and why they work.

Look for more coverage of Small Business Week 2012.

Related: Small Business and the President's Cabinet (Video)

Related: The SBA's Karen G. Mills on the Small-Business Recovery (Video)

Related: SBA Chief Karen G. Mills on the Small-Business Lending Comeback (Video)