In the last several years, much has been written about growing economic challenges, increasing income inequality, and political polarization in the United States. This book argues that lessons for addressing these national challenges are emerging from a new set of realities in America's metropolitan regions: first, that inequity is, in fact, bad for economic growth; second, that bringing together the concerns of equity and growth requires concerted local action; and, third, that the fundamental building block for doing this is the creation of diverse and dynamic epistemic (or knowledge) communities, which help to overcome political polarization and help regions address the challenges of economic restructuring and social divides.