Cass R. Sunstein, Parking the Big Money, New York Review of Books:
The fractions of wealth held abroad are highly variable. In Europe, it is about 10 percent. In African and Latin countries, it is much higher—between 20 percent and 30 percent. In Russia, it is a whopping 52 percent. ...
According to Zucman [The Hidden Wealth of Nations: The Scourge of Tax Havens by Gabriel Zucman], the United States is losing $35 billion in annual taxes, and some estimates say that the real loss is as high as $100 billion. If so, and if those who successfully evade taxes are mostly the wealthiest people, there is a serious problem. By way of comparison, the entire annual budget of the Department of State is in the vicinity of $50 billion. ...