think tank

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A group or institution organized for intensive research and solving of problems, especially in the areas of technology, social or political strategy, or armament.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun idiomatic A group of people who collectively perform research and develop reports and recommendations on topics relating to strategic planning or public policy, and which is usually funded by corporate, government, or special interests.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a company that does research for hire and issues reports on the implications