The Fifth Estate : Brookings Institution Press : 9780815728306 : 0815728301 : 13 Sep 2016 : "What role do think tanks play in shaping public policy and public discourse in the United States? In The Fifth Estate: Think Tanks, Public Policy, and Governance, James G. McGann illustrates how policymakers have come to value the independent analysis and advice provided by think tanks and why it has become one of the defining characteristics of the American political system. Drawing on case studies in both foreign and domestic policy, McGann clarifies the correlation between think tank research and the policies enacted by the past three presidential administrations. He also describes a phenomenon known as "the revolving door," where think tanks provide former government officials an opportunity to share insights from public service, remain involved in policy debates, and continue to provide advice and commentary. Based on the history and the level of involvement seen today, the influence of