The 2011 Global Go To Think Tank Rankings marks the fifth edition of the annual report. As in previous years, the Think Tanks and Civil Societies Program (TTCSP) at the University of Pennsylvania’s International Relations Program has relied on the indexing criteria and process developed by James G. McGann for ranking think tanks around the world. The Program’s Rankings remain the first and most comprehensive ranking of the world’s top think tanks, and are based on an annual global peer and expert survey of close to 1500 scholars, policymakers, journalists, and regional and subject area experts. Given the rigor and scope of the process, the Rankings produced have been described as the insider’s guide to the global marketplace of ideas. As part of the process, all 6,545 think tanks in the world were contacted and encouraged to participate in the nominations process as well as a group of over 6000 journalists, policymakers, public and private donors, think tanks, and regional and subject area specialists. This group of peers and experts were surveyed to nominate and then rank public policy research centers of excellence for 2011. Additionally, the Program has assembled a set of Expert Panels, comprising over 793 expert members from around the world, spanning the political spectrum and drawing from a wide variety of disciplines and sectors, to help in the refining and validation of the lists generated. These experts were consulted at every stage in the process. The nominations and rankings were based on the detailed set of criteria that included the think tanks’ production of rigorous and relevant research, publications, and programs in one or more substantive areas of research