The headquarters of local think tanks—such as the libertarian Cato Institute on Massachusetts Avenue in DC—are the factories of Washington’s only native industry. Photograph courtesy of the Cato Institute.

This article initially appeared in the August issue of The Washingtonian. For more on the area's top think-tank leaders, including what they earn, click here.

America has been defined by its great cities and their signature industries. Pittsburgh became the city of steel during the industrial age. During the first half of the 20th century, Detroit became the city of automobiles. Los Angeles led the rise of film and television. More recently, California’s Silicon Valley spearheaded the technology boom, and New York is synonymous with Wall Street.

Washington has always been different. It has never had much of a manufacturing base, and since Georgetown ceased to be an active port in the late 18th century, it hasn’t exported many products. In fact, Washington “makes” very little. Yet there is one industry that Washington can claim as its own: the ideas industry.

Travel down Massachusetts Avenue in Northwest DC and you’ll find yourself in the heart of an industry that was, when it began, unique to the nation’s capital. The imposing facades of the Brookings Institution, the Carnegie Endowment for International Peace, and the Johns Hopkins School of Advanced International Studies bear little resemblance to the old steel mills of Pittsburgh, but they are factories all the same—producing an endless stream of books, policy papers, reports, analyses, and commentary on everything from health care to taxes to defense.

Washington’s “ideas” economy, based in its think tanks and universities, has made the city an intellectual leader. In 2009, the University of Pennsylvania conducted a survey of the world’s think tanks. It identified 6,305 in 169 countries. At the center of this universe was Washington. Some 393 think tanks were located in the District, more than in any other city in the world; DC is home to about one-fifth of all the think tanks in the United States. Another 149 are in Virginia and Maryland. With budgets ranging from a few hundred thousand dollars to $80 million, the ideas industry is a huge driver of the local economy.

And it’s not just a matter of numbers. When the think tanks in the survey were rated for the influence of their work, nine of the top ten in the United States had offices in Washington; the Hoover Institution at Stanford University—staffed with many DC refugees—was the only non-DC think tank to make the top ten.

Results were similar when think tanks were broken down into specialties. All of the world’s top five that work on environmental issues are in DC. Indeed, in almost every area of importance, Washington came out on top, with four of the top five in international economics and international affairs and three of the top five each in health policy and social policy. When it came to ranking the world’s think tanks according to overall influence and respect, the winner was the Brookings Institution, formed in 1916 by the Midwestern industrialist Robert Brookings. Coming in second was its next-door neighbor, the Carnegie Endowment for International Peace. The previous year, Brookings had tied for the top with the Peterson Institute for International Economics, across the street. If Washington is the center of the think-tank universe, the 1700 block of Massachusetts Avenue, just off Dupont Circle, is ground zero.