Warren E. Buffett, chairman of Berkshire Hathaway Inc., said Sunday that he regarded efforts to rate the performance of companies on social, human rights or environmental measures to be of dubious merit and would not consider such factors when selecting investments...Buffett "is ignoring the positions of thousands of companies and of investors with tens of trillions of dollars who strongly believe that environmental, social and governance issues can and do affect shareholder value," said Timothy Smith, chairman of the Social Investment Forum...[refers to ExxonMobil, Altria, PetroChina]