The government does not make public any reasons citizens may have given for renouncing U.S. citizenship, making it impossible to say for certain what has driven the sharp rise in demand. But the most likely cause appears to be the Obama-era crackdown on U.S. citizens hiding wealth overseas.
From 2001 to 2008, 3,937 people who had lived on U.S. soil for at least eight years either renounced their citizenship or gave up lawful permanent resident status, according to Andrew Mitchel, an international tax attorney in Centerbrook, Connecticut, who tracks the figures closely.
From January 2009 to the quarter ending June 30, 2014, the number rose to 9,566, according to a Yahoo News analysis of the figures published on a quarterly basis by the Internal Revenue Service.
The rise has coincided with a campaign that has scooped up about $6 billion in taxes, interest and penalties from more than 40,000 U.S. taxpayers since 2009.