In my (limited) exposure to the think tank "industry", it seems that many make a fair chunk of their bottom line through memberships; companies buy memberships to receive publications & analysis, newsletters, networking opportunities and a voice in any policy processes the think tank can get involved in.
Some member companies will pay, partially or fully, for their memberships with services rendered; which means the think tanks have ready access to good and plentiful legal representation & financial advice/management, which must help lower costs quite a lot.
Some member companies will pay, partially or fully, for their memberships with services rendered; which means the think tanks have ready access to good and plentiful legal representation & financial advice/management, which must help lower costs quite a lot.