Familiar Wall Street, European, and other global financial institutions comprise them.
Current data gotten from global central banks, the World Bank, IMF, UN, and national accounts were used. Other evidence includes:
(1) "Transfer mispricing" data.
(2) Demand for cross-border liquid "mattress money" data.
(3) Current research data on the offshore private banking market's size.
TJN believes its work comprises the "most rigorous and comprehensive" data ever produced. It challenges anyone to contest it.
In overall size through 2010, it estimates hidden global wealth at from $21 - $32 trillion. It's invested "virtually tax-free" through a still-expanding black hole of more than 80 secret jurisdictions. It calls estimates conservative.
Developed countries don't face debt problems. They've got huge offshore tax evasion ones. Repatriation would reduce debt substantially. Doing so would bring it well within tolerable levels.