From ABC News:
First wealth. A recently released study says that the inequality in wealth throughout the world is extreme and growing more so. The report by the World Institute for Development Economics Research of the United Nations University paints an informative picture of the world’s wealth distribution as of 2000, the last year for which figures are available. It states that the top 1% of the world’s population – about 37 million adults – had net assets (note: not income) worth at least $500,000. This constituted approximately 40% of the world’s assets.
In contrast, the top 50% of the world’s people owned a bit less than 99% of the wealth, and this translated into a median wealth (half the world’s population having more, half less) of just over $2,000. To be in the top 10% required net assets worth about $60,000.