Even some who acknowledge tax worries say decisions to renounce are far more complicated than a simple desire to avoid paying.
Peter Dunn, born in Chicago and raised in Alaska, moved to Canada to pursue a graduate degree in theology. He met his wife, Catherine, and they made Toronto home when her work as one of the owners of an aviation maintenance firm made her the breadwinner.
Dunn remained an American. But he was alarmed by a change in U.S. law requiring those with more than $2 million in assets to pay an exit tax if they gave up citizenship. He didn't have $2 million. But his wife was doing well enough that he imagined one day they could get there. The idea of the U.S. government taxing his Canadian wife's money didn't seem right.
"When I learned about that, I decided that to protect my wife, I better expatriate," he says.
Corine Mauch arrived at the same decision by a different route. Mauch was born a U.S. citizen to Swiss parents who were college students in Iowa. They lived in the U.S. until she was 5, then again for two more years before she turned 11. Mauch maintained dual citizenship even after she was elected to Zurich's city council. But when she became mayor, she reconsidered.
During the last American presidential election, "I asked myself 'Where do I feel at home?' And the answer is clear: In Zurich and in Switzerland. My attachment to America is limited to my very early youth," Mauch said. Double taxation was "not the crucial factor for my decision. But I will not miss the U.S. tax bureaucracy either."
Taxes play little or no role in other decisions.
Norman Heinrichs-Gale's parents were missionaries from Washington state who raised him in Asia and the Middle East. In 1986, he traveled to Austria with his American wife, and they found work at a conference center in an alpine valley town of 6,000. The jobs were supposed to last a year. But the couple stayed, sending their children to local schools.