Depending on who you believe this statement may or may not reflect the truth. But it is beyond doubt that a tiny number of Super Rich control a vastly disproportionate share of global wealth. It does not matter whether they number 100, 400 or 1000. The sad story is that beyond the establishment Economists focus so little on the issue of inequality in incomes and wealth. Maybe this is due to the fact that most of them are just little cogs in the system that seems to be designed to create these disparities. They work in safe jobs in Universities - usually taxpayer-funded jobs for life - or in 'independent' think tanks or research institutes that are either taxpayer-funded or funded by rich individual that act as 'sponsors' or 'trustees'. Employer organisations and Financial Institutions also keep a stable of Economist but these can also hardly be expected to bit the hand that feeds them.
