There are now more than 2,000 billionaires living in 20 countries from the United States, China and Russia to Turkey, Thailand, and Indonesia. An annual wealth tax levied at just 1.5 percent of their net worth would raise $74 billion each year: that alone would be enough to fill the funding gap to get every child into school and deliver essential health services in all low-income countries.

— Doughnut Economics: Seven Ways to Think Like a 21st-Century Economist by Kate Raworth