That might have to do with the fact that American CEOs are significantly better paid than those from anywhere else.
A Fortune 500 CEO in the United States makes more than 12 million dollars per year, nearly five million dollars more than the amount for top CEOs in Switzerland, where the second highest paid CEOs live, more than twice that for those in Germany, where the third highest paid CEOs reside, and more than twenty one times that for those in Poland. In Switzerland, the country with the second largest CEO-to-worker pay gap, chief executives make 148 times as much as the average worker; in Germany, the country with the third largest gap, CEOs make 147 times more; and in Spain, the country with the fourth largest gap, the ratio is 127 to one.
Read more at Washington Post