The Cato Institute is a libertarian think tank headquartered in Washington, D.C. It was founded in 1977 by Edward H. Crane, who remained president and CEO for 35 years until 2012, when he was replaced by John A. Allison; and Charles Koch, chairman of the board and chief executive officer of the conglomerate Koch Industries, Inc., the second largest privately held company (after Cargill) by revenue in the United States.
The Institute's stated mission is "to broaden the parameters of public policy debate to allow consideration of the traditional American principles of limited government, individual liberty, free markets, and peace" by striving "to achieve greater involvement of the intelligent, lay public in questions of policy and the proper role of government". Cato scholars conduct policy research on a broad range of public policy issues and produce books, studies, op-eds and blog posts. They are also frequent guests in the media.
Cato scholars were critical of George W. Bush's Republican administration (2001–2009) on several issues, including the Iraq War, civil liberties, education, agriculture, energy policy and excessive government spending. On other issues, most notably health care, Social Security, global warming, tax policy and immigration, Cato scholars praised Bush administration initiatives. During the 2008 presidential election, Cato scholars criticized both major-party candidates, John McCain and Barack Obama.
The Cato Institute was named the fifth-ranked think tank in the world for 2009 in a study of leading think tanks by James G. McGann, Ph.D. of the University of Pennsylvania, based on a criterion of excellence in "producing rigorous and relevant research, publications and programs in one or more substantive areas of research". It has been called "Washington's premier libertarian think tank".