Top 100 Think Tanks – United States – Penn Libraries – University of Pennsylvania Principles of Government · September 21, 2020 · Top 100 Think Tanks – United States In rank order Brookings Center for Strategic and International Studies Carnegie Endowment for International Peace Heritage Foundation Peterson Institute for International Economics (PIIE) Urban Institute Woodrow Wilson International Center for Scholars Center for American Progress (CAP) Atlantic Council RAND Corporation Hudson Institute Council on Foreign Relations (CFR) Belfer Center for Science and International Affairs Cato Institute Center for New American Security (CNAS) American Enterprise Institute for Public Policy Research (AEI) — United States James A. Baker III Institute for Public Policy Stimson Center Human Rights Watch Resources for the Future (RFF) Freedom House German Marshall Fund of the United States (GMF) Hoover Institution World Resources Institute (WRI) McKinsey Global Institute National Bureau of Economic Research Inter-American Dialogue Information Technology and Innovation Foundation (ITIF) Center for Global Development (CGD) Chicago Council on Global Affairs United States Institute of Peace (USIP) Acton Institute for Study of Religion and Liberty Pew Research Center Center on Budget and Policy Priorities (CBPP) Manhattan Institute for Policy Research (MI) Economic Policy Institute (EPI) National Bureau of Asian Research (NBR) Worldwatch Institute Mercatus Center Carnegie Council for Ethics in International Affairs Migration Policy Institute (MPI) Independent Institute Center for Climate and Energy Solutions (C2ES) Middle East Institute (MEI) Earth Institute Center for the National Interest (CFTNI) Bipartisan Policy Center (BPC) Aspen Institute EastWest Institute (EWI) New America Foundation Center for Transatlantic Relations (CTR) Joint Center for Political and Economic Studies Foreign Policy Research Institute (FPRI) Atlas Network Foundation for Economic Education (FEE) Reason Foundation Institute for Policy Studies (IPS) Milken Institute International Food Policy Research Institute (IFPRI) Center for Economic and Policy Research (CEPR) Third Way Committee for Economic Development Center for European Policy Analysis (CEPA) Center for Strategic and Budgetary Assessments (CSBA) McCain Institute for International Leadership Hispanic American Center for Economic Research (HACER) Open Society Foundations (OSF) Competitive Enterprise Institute (CEI) Institute for Women’s Policy Research (IWPR) Arctic Institute R Street Institute Center for International Security and Arms Control (CISAC) Lugar Center Institute for New Economic Thinking Berggruen Institute Demos Congressional Research Service Africa Center for Strategic Studies Project for the Study of the 21st Century (PS21) Institute of Religion and Democracy (IRD) Institute for Science and International Security (ISIS) Mackinac Center Center for International Policy Washington Center for Equitable Growth Center for Naval Analyses Institute for Defense Analyses Levy Institute Public Policy Institute of California Goldwater Institute Roosevelt Institute Institute for the Study of War (ISR) Center for Immigration Studies Center for National Policy Pacific Council on International Policy Center for International Development (CID) Pacific Forum Beacon Hill Institute Center for Governmental Research American Foreign Policy Council J Street Federation for American Immigration Reform Penn Library page – website