As President Obama announces his deficit reduction plan, which includes the 'Buffett Rule', to increase taxes on America's richest, Profile looks at the billionaire investor Warren Buffett. At 81 years of age, he's one of the richest men in the world closing in on a personal fortune of nearly 40 billion dollars. Recently Buffett decided to do a small tax survey in his Omaha office to find out what proportion of everybody's salary was being taxed. He discovered that he was paying a much lower share of his income in tax than his staff. So he proposed that that America's tax laws be changed so that he and his "mega-rich friends" pay more income tax. President Obama took the call. Mary Ann Sieghart talks to family, friends and Buffett experts to get an insight into the man known as the 'Oracle of Omaha' who many say has inspired a new American tax system.Producer Deiniol Buxton.