• The American Enterprise Institute
• Asia-Pacific Policy Program (Harvard University)
• The Aspen Institute
• Ashbrook Center for Public Affairs (Ashland University, Ohio)
• Brookings Institution
• BRIE - The Berkeley Roundtable on the International Economy (University of California, Berkeley)
• The Carter Center (Emory University)
• Cascade Policy Institute
• Cato Institute
• Center for Congressional and Presidential Studies (American University)
• Center for Democracy and Technology
• Center for Law and Social Policy
• The Center for National Policy
• Center for Public Integrity
• Center for Public Justice
• Center for Security Studies and Conflict Resolution (Zurich, Switzerland)
• Center for Strategic and Budgetary Assessments
• CSIS - Center for Strategic and International Studies ==> Analysis of current and emerging global issues.
• Center for the American Woman and Politics (Rutgers University)
• Center on Budget and Policy Priorities
• Center on Religion and Democracy
• The Century Foundation(formerly the Twentieth Century Fund)
• Committee for Economic Development
• Commonwealth Institute
• Project on Defense Alternatives
• Competitive Enterprise Institute
• CIESIN - Consortium for International Earth Science Information Network Council on Faith and International Affairs
• Democratic Leadership Council
• Development Gateway  
• Ethics and Public Policy Center
• Freedom Forum
• George C. Marshall Institute
• Heritage Foundation
• Hoover Institution on War, Revolution, and Peace
• Hudson Institute
• Humphrey Institute 
• The Independent Institute
• Institute for Agriculture & Trade Policy
• Institute for Fiscal Studies(United Kingdom)
• The Institute for Global Engagement
• Institute for International Economics
• Institute for Philosophy and Public Policy (University of Maryland)
• Institute for Policy Analysis (University of Toronto)
• Institute for Policy Research (Northwestern University)
• Institute for Research on Poverty (University of Wisconsin - Madison)
• Institute for the Study of Diplomacy (Georgetown University)
• Institute for Women's Policy Research (IWPR)
• Institute of Public Policy (George Mason University)
• InterAction
• International Center for Religion and Diplomacy
• IIASA - The International Institute for Applied Systems Analysis
• International Institute for Strategic Studies
• Jerome Levy Economics Institute (Bard College - Annandale-on-Hudson, New York)
• Joint Center for Political & Economic Studies
• Joint Center for Poverty Research (Northwestern University / University of Chicago)
• Massachusetts Institute for a New Commonwealth
• Media Studies Center
• Milken Institute (Santa Monica, CA)
• National Academy of Public Administration
• National Bureau of Economic Research (Cambridge, Massachusetts)
• National Center for Children in Poverty (Columbia University)
• National Center for Policy Analysis (Dallas, TX) 
• Northeast-Midwest Institute
• Oxfam International
• Pacific Research Institute for Public Policy
• Pioneer Institute for Public Policy Research (Boston, Massachusetts)
• Policy.com
• Political Research Associates
• Progress and Freedom Foundation
• Public Agenda
• Public Policy Institute of California (PPIC)
• Public Policy Research Center (University of Missouri, St. Louis)
• Rand Corporation
• Reason Foundation
• Resources for the Future (RFF)
• The Nelson A. Rockefeller Institute of Government
• SIPRI - Stockholm International Peace Research Institute
• Henry L. Stimson Center
• Strategic Studies Institute (U.S. Army War College) 
• TRAC: Transactional Records Access Clearinghouse (Syracuse University)
  Catalog of computerized data files on federal law enforcement activities
• Twentieth Century Fund
• Urban Institute (Washington, D.C.)
• United States Institute of Peace
• World Resources Institute (Washington, D.C.)
• World Conservation Monitoring Centre (Cambridge, United Kingdom)
• Worldwatch Institute

Additional Resources

• Electronic Policy Network
• International Relations and Security Network (Center for Security Studies and Conflict Resolution) links to world-wide organizations, publications, and discussion groups
• NIRA 2002 World Directory of Think Tanks (The National Institute for Research Advancement, Japan) 
• Free-Market.Net