 The report says the current effective tax rate on these individuals is about 0.3%, and the intention is to hike it up to at least 2% of wealth, which would raise, they say, about $200 to $250 billion a year. Now, it's unclear how exactly this tax would be implemented, but it would require international cooperation, and the United States, which is home to many of the world's wealthiest, is opposed to the plan.