These are tough times for Washington's roughly 400 think tanks — the policy factories where scholars get paid to study issues and give politicians advice. Powerful external forces are reshaping the industry.

One current example is the left-leaning New America Foundation, founded in 1999. It works on public policies for the digital age. Last month it landed in the think tank industry's latest money controversy.

The condensed version: New America had a program that studied monopolies and how to fight them. Last month the think tank's president, Anne-Marie Slaughter, closed it down. Program director Barry C. Lynn said the ax fell because he criticized Google as monopolistic. Google and its former CEO, Eric Schmidt, are among New America's biggest funders.

New America says Google had nothing to do with the decision, which it says concerned Lynn's working relationships with colleagues. A spokesman said that if any funders suggested firing a foundation staffer, they would be "categorically refused."

The anti-monopoly program is now its own think tank, the Open Markets Institute.

"Just common sense tells you that having these big companies in this space is going to have an influence, and it's not a good influence," says Zephyr Teachout, who resigned as a fellow at New America to become chair of the new think tank's board.

Washington got its first think tanks a century ago. For a long time, they presented themselves as universities without students.

But that's history now, said sociologist Thomas Medvetz, author of the book Think Tanks in America. He said think tank experts now need skills not commonly found on college campuses: "Skills that one would use in a PR firm, for example, or a lobbying firm, as an aide on Capitol Hill, as a scholar, or a journalist."

Another seismic shift involves the funding for think tanks. Once they lived on broad grants, from foundations and reticent millionaires. But now, the funders are often wealthy business people — in modern jargon, philanthro-capitalists — notably many from the tech industry.

Their giving is usually targeted to a program, an expert or even a single project.

Political scientist Daniel Drezner, author of The Ideas Industry, said, "You are seeing, interestingly enough, traditional foundations as well as sort of the new generation of philanthro-capitalists, being very much obsessed with impact — which is to say, they want to know exactly what they're getting for their dollars' worth."

This targeted giving has forced many think tanks to change the way they operate.

Arthur Brooks — president of the American Enterprise Institute, the oldest of the conservative think tanks — said in 2015 that his job involved "150 speeches a year, which is what modern think tank presidents need to do, because we spend 75 percent of our time raising funds."

There's every expectation the time and money pressures will keep increasing. "These trends create a much different environment than think tanks operated in 15 and certainly 20 years ago," said James McGann, director of the Think Tanks and Civil Societies Program at the University of Pennsylvania.

He said social media is bringing still more changes, pointing to President Trump on Twitter as an example. "He tweets, and essentially disrupts the agenda, disrupts the news cycle, throws everyone off kilter."

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