It is already in the interest of think tanks to be transparent. Think tanks exist in societies that depend on open communication and the free flow of ideas. Numerous organisations exist to criticise and unmask non-transparent think tanks: [1] this is sufficient incentive for them to reveal their funding. There may be exceptions in which the benefits of non-disclosure overrule the disadvantages in terms of trust, but these are rare, and it does not follow that it will be abused.  [1] Who Funds You, Political Innovation,