In financial disclosures released Thursday, President Obama and his wife Michelle revealed they were worth as much as $7 million in 2013. A chunk of the wealth comes from Treasury notes held by the couple, worth between $1 million and $5 million. Most of the income for the president comes from his book royalties. His 1995 “Dreams From My Father,” garners $50,001 to $100,000, while “The Audacity of Hope" from 2006 nets between $15,001 and $50,000 a year. In comparison, Vice President Joe Biden’s royalties from 2007’s “Promises to Keep” earned him less than $201.