A think tank is a group of intellectuals and experts that devote their time towards solving complex issues within their field of study. Most commonly, these institutions tend to be devoted towards economics, political science, public policy, and international relations. If memory serves me, the term arose right around the time RAND corporation began to bloom. Organizations like RAND would work for the Pentagon on defense issues, and were dubbed "think tanks" because of their military affiliation. [i]The More You Know![/i]