Think tanks don’t have any legislative power. At the end of the day, what they do is merely make suggestions. If they were active lobbyists they would lose their privileged legal position as an academic organisation. [1] Even if there may be other benefits of them being transparent, the legal concept of transparency cannot be extended to them. That would open the door to forcing other independent private institutions to reveal details of their organisation. Furthermore, think tanks rarely claim to be completely impartial. They usually have an agenda and are aligned with a political party. This concession in terms of impartiality merits equal concessions in terms of demanded transparency. At the end of the day it is their work that influences the agenda and that same work shows where their sympathies lie.  [1] “The Political Activity of Think Tanks: The Case for Mandatory Contributor Disclosure”, Harvard Law Review, Vol. 115, No. 5, March 2002, pp. 1502-1524.