Think Tank Search searches the websites of institutions that generate public policy research, analysis, and activity. These sites are affiliated with universities, governments, advocacy groups, foundations, and non-governmental organizations. Inclusion is based upon the relevancy of subject area to HKS coursework and scholarship, the availability of the think tank’s research in full-text on the website, and the think tank’s reputation and influence upon policy making. The list represents a mixture of partisan and non-partisan think tanks.

The Global Go To Think Tank Index is the result of an international survey of over 1,950 scholars, public and private donors, policy makers, and journalists who helped rank more than 6,500 think tanks using a set of 18 criteria developed by the TTCSP.

The Brookings Institution is a nonprofit public policy organization based in Washington, DC. Our mission is to conduct in-depth research that leads to new ideas for solving problems facing society at the local, national and global level.

In a complex, changing, and increasingly contested world, the Carnegie Endowment helps countries take on the most difficult global problems and safeguard peace and security through independent analysis, strategic ideas, support for diplomacy, and training the next generation of international scholar-practitioners.

In a complex, changing, and increasingly contested world, the Carnegie Endowment helps countries take on the most difficult global problems and safeguard peace and security through independent analysis, strategic ideas, support for diplomacy, and training the next generation of international scholar-practitioners.

The Center for American Progress is an independent, nonpartisan policy institute that is dedicated to improving the lives of all Americans through bold, progressive ideas, as well as strong leadership and concerted action. Our aim is not just to change the conversation, but to change the country.

The Center for Strategic and International Studies (CSIS) is a bipartisan, nonprofit policy research organization dedicated to advancing practical ideas to address the world’s greatest challenges.

Chatham House has been a source of independent analysis, trusted dialogue and influential ideas for one hundred years. Today, at the beginning of our second century, we continue to offer solutions to global challenges and actively seek to empower the next generation to change their world.

The Council on Foreign Relations (CFR) is an independent, nonpartisan membership organization, think tank, and publisher dedicated to being a resource for its members, government officials, business executives, journalists, educators and students, civic and religious leaders, and other interested citizens in order to help them better understand the world and the foreign policy choices facing the United States and other countries. Founded in 1921, CFR takes no institutional positions on matters of policy. Our goal is to start a conversation in this country about the need for Americans to better understand the world.

The Center for International Development (CID) is a university-wide center based at the Harvard Kennedy School that seeks to solve these pressing development problems—and many more.

Heritage’s mission is to formulate and promote public policies based on the principles of free enterprise, limited government, individual freedom, traditional American values, and a strong national defense.

With its eminent scholars and world-renowned Library and Archives, the Hoover Institution is a public policy think tank that seeks to improve the human condition by advancing ideas that promote economic opportunity and prosperity, while securing and safeguarding peace for America and all mankind.

Our library was established in the 1960s, primarily to meet the needs of the institute's researchers. It currently holds a collection of approximately 30,000 book volumes. The main fields covered are peace research, conflict studies, security issues, disarmament, development studies, international law pertaining to armed conflict, and international affairs. The holdings include extensive Johan Galtung and Mahatma Gandhi collections. In addition, the library receives approximately 430 journals on a regular basis.

"The National Bureau of Economic Research (NBER) is a private, nonpartisan organization that facilitates cutting-edge investigation and analysis of major economic issues. It disseminates research findings to academics, public and private-sector decision-makers, and the public by posting more than 1,200 working papers and convening more than 120 scholarly conferences, each year."

Pew Research Center is a nonpartisan fact tank that informs the public about the issues, attitudes and trends shaping the world. We conduct public opinion polling, demographic research, content analysis and other data-driven social science research. We do not take policy positions.

The Peterson Institute for International Economics (PIIE) is an independent nonprofit, nonpartisan research organization dedicated to strengthening prosperity and human welfare in the global economy through expert analysis and practical policy solutions.

The Public Policy Institute of California (PPIC) is a nonprofit, nonpartisan think tank. Our mission is to inform and improve public policy in California through independent, objective, nonpartisan research.

RAND is a research organization that develops solutions to public policy challenges to help make communities throughout the world safer and more secure, healthier and more prosperous.

RFF’s mission is to improve environmental, energy, and natural resource decisions through impartial economic research and policy engagement.

The Russell Sage Foundation was established by Margaret Olivia Sage in 1907 for “the improvement of social and living conditions in the United States.” It dedicates itself to strengthening the methods, data, and theoretical core of the social sciences in order to better understand societal problems and develop informed responses. The foundation supports visiting scholars in residence and publishes books and a journal under its own imprint. It also funds researchers at other institutions and supports programs intended to develop new generations of social scientists.

SIPRI is an independent international institute dedicated to research into conflict, armaments, arms control and disarmament. Established in 1966, SIPRI provides data, analysis and recommendations, based on open sources, to policymakers, researchers, media and the interested public. Based in Stockholm, SIPRI is regularly ranked among the most respected think tanks worldwide.