Thirteen CEOs major U.S. business and finance corporations (including JPMorgan Chase, Berkshire Hathaway, General Motors, T. Rowe Price and Vanguard) have developed what they call “Commonsense Corporate governance Principles to make corporate governance more responsible. Here are key provisions set out in an open letter signed by all 13 CEOs: 1. Truly independent corporate boards are vital to effective governance, so …