Top Think Tanks Worldwide (US and Non-US):
- Brookings
- Chatham House
- Carnegie Endowment for International Peace (CEIP)
- Center for Strategic and International Studies (CSIS)
- Bruegel
- Stockholm International Peace Research Institute (SIPRI)
- RAND Corporation
- Council on Foreign Relations (CFR)
- International Institute for Strategic Studies (IISS)
- Wilson Center
- Amnesty International (AI)
- Transparency International (TI)
- Japan Institute of International Affairs (JIIA)
- German Institute for International and Security Affairs
- Peterson Institute for International Economics (PIIE)
- Cato Institute
- Heritage Foundation
- Fundacao Getulio Vargas (FGV)
- Fraser Institute
- French Institute of International Relations (IFRI)
Top Think Tanks in the US:
- Brookings
- CEIP
- CSIS
- CFR
- Wilson Center
- RAND Corporation
- Pew Research Center
- Cato Institute
- Heritage Foundation
- Center for American Progress (CAP)
- National Bureau of Economic Research (NBER)
- American Enterprise Institute (AEI)
- PIIE
- Center for a New American Security (CNAS)
- World Resources Institute (WRI)
- Atlantic Council
- Carnegie Council for Ethics in International Affairs
- James A. Baker III Institute for Public Policy
- Hoover Institution
- Urban Institute
Top Think Tanks Worldwide (Non-US):
- Chatham House
- Bruegel
- SIPRI
- IISS
- Transparency International
- French Institute of International Relations (IFRI)
- Amnesty International (AI)
- Centre for European Policy Studies (CEPS)
- Korea Development Institute (KDI)
- Danish Institute for International Studies (DIIS)
Top Think Tanks in Mexico and Canada:
- Fraser Institute
- Consejo Mexicano de Asuntos Internacionales (COMEXI)
- Fundar, Centro de Analisis e Investigacion
- Centro de Investigacion y Docencia Economicas (CIDE)
- C.D. Howe Institute
Top Think Tanks in China, India, Japan, and Korea:
- Korea Development Institute (KDI)
- Japan Institute for International Affairs (JIIA)
- China Institute of International Studies (CIIS)
- Korea Institute for International Economic Policy (KEIP)
- China Institutes of Contemporary International Relations (CICIR)
Top Think Tanks in Southeast Asia and the Pacific:
- Australian Institute for International Affairs (AIIA)
- Centre for Strategic and International Studies (CSIS)
- Centre for Strategic Studies (CSS)
- Singapore Institute of International Affairs (SIIA)
- Lowy Institute for International Policy
Top Think Tanks in Sub-Saharan Africa:
- Kenya Institute for Public Policy Research and Analysis (KIPPRA)
- IMANI Center for Policy and Education
- South Africa Institute of International Affairs (SAIIA)
- Council for the Development of Social Science Research in Africa (CODESRIA)
- Botswana Institute for Development Policy Analysis (BIDPA)
Top Think Tanks in Central and South America:
- Fundacao Getulio Vargas (FGV)
- Comision Economica para America Latina (CEPAL)
- Centro de Implementacion de Politicas Publicas para la Equidad y el Crecimiento (CIPPEC)
- Centro Brasiliero de Relacoes Internacionais (CEBRI)
- Consejo Argentina para las Relaciones Internacionales (CARI)
Top Think Tanks in Central Asia:
- Center for Economic and Social Development (CESD)
- Kazakhstan Institute for Strategic Studies (KazISS)
- Caucuses Research Resource Center (CRRC)
- Armat Center for the Development of Democracy and Civil Society
- Aga Khan Foundation (AKF)
Top Think Tanks in the Middle East and North Africa (MENA):
- Carnegie Middle East Center
- Al-Ahram Center for Political and Strategic Studies (ACPSS)
- Brookings Doha Center
- Center for Economics and Foreign Policy Studies (EDAM)
- Institute for National Security Studies (INSS)
Top Think Tanks in Western Europe:
- Chatham House
- Bruegel
- Stockholm International Peace Research Institute (SIPRI)
- French Institute of International Relations (IFRI)
- Amnesty International (AI)
Top Think Tanks in Central and Eastern Europe:
- Carnegie Moscow Center
- Center for Social and Economic Research (CASE)
- Polish International of International Affairs (PISM)
- Institute of World Economy and International Relations (IMEMO RAS)
- Razumkov Centre
Top Defense and Security Think Tanks:
- CSIS
- RAND Corp.
- IISS
- Brookings
- Chatham House
Top Foreign Policy and International Affairs:
- Brookings
- Chatham House
- CEIP
- CFR
- CSIS
Top Domestic Economic Policy Think Tanks:
- Brookings
- National Bureau of Economic Research (NBER)
- Adam Smith Institute (ASI)
- PIIE
- Cato Institute
Top Energy and Resource Policy Think Tanks:
- Oxford Institute for Energy Studies (OIES)
- World Resources Institute (WRI)
- Institute of Energy Economics
- James A. Baker III Institute for Public Policy
- RAND Corp.
Top Environment Think Tanks:
- World Resources Institute (WRI)
- Stockholm Environment Institute (SEI)
- Worldwatch Institute
- Brookings
- Center for Climate and Energy Studies (C2ES)
Top Foreign Policy and International Affairs Think Tanks:
- Brookings
- Chatham House
- CEIP
- CFR
- CSIS
Best For-Profit Think Tanks:
- Economist Intelligence Unit (EIU)
- McKinsey Global Institute
- Google Ideas
- Ernst and Young (EY)
- Deutsche Bank Research
Top Education Policy Think Tanks:
- Urban Institute
- RAND Corporation
- Brookings
- Cato Institute
- National Institute for Educational Policy Research (NIER)
Top Domestic Health Policy Think Tanks:
- Cambridge Centre for Health Services Research (CCHSR)
- RAND Corporation
- Brookings
- Bloomberg School of Public Health Research Centers (JHSPH)
- Fraser Institute
The full think tank report can be read here. Also, here is a press release from UPenn on the think tank rankings.
By the way, you may want to be careful reading too much into think tank rankings.
