Bernie Sanders has accused Tesla CEO, Elon Musk, of paying a tax rate of less than 3.3% compared to the average truck driver, nurse, and teacher. This comes amid renewed debate over billionaire taxation in the U.S. According to the Bloomberg Billionaire Index, Musk's net worth now stands at $637 billion, making him the world's wealthiest person. Last year, he became the first individual to surpass $500 billion in net worth and plans to pay roughly the same amount in taxes over his lifetime.