The most comprehensive study of personal wealth ever undertaken also reports that the richest 1% of adults alone owned 40% of global assets in the year 2000, and that the richest 10% of adults accounted for 85% of the world total. In contrast, the bottom half of the world adult population owned barely 1% of global wealth.

The UNU-WIDER study is the first of its kind to cover all countries in the world and all major components of household wealth, including financial assets and debts, land, buildings and other tangible property.

'One should be clear about what is meant by 'wealth',' say co-authors James Davies of the University of Western Ontario, Anthony Shorrocks and Susanna Sandstrom of UNU-WIDER, and Edward Wolff of New York University.

'We use the term in its long-established sense of net worth: the value of physical and financial assets less debts. In this respect, wealth represents the ownership of capital. Although capital is only one part of personal resources, it is widely believed to have a disproportionate impact on household wellbeing and economic success, and more broadly on economic development and growth.'