Listed companies in the US have been given 11 months to implement a set of new governance principles published this week by a coalition of the world's largest institutional investors. The six principles include the end of dual class shares and the introduction of annual votes on the re-election of board members. The investors, known as the Investor Stewardship Group (ISG)—with members including BlackRock, Vanguard and CalSTRS, and a total of $17trn under management—also emphasised an expectation that boards have independent leadership—though the ISG concedes that its membership is split over whether this requires an independent chairman. A statement on the group's website says: "The ISG encourages shareholders’ elected