"...After nearly two decades of investing in emerging markets, much of it traveling from the gritty alleys of Bihar to the rooftop helipads of Sao Paulo in search of opportunity, I’ve developed an unusual rule of the road: watch the changes in the list of top billionaires, learn how they made their billions, and note how many billions they made. Changes in the list, and the size and source of the fortunes, can provide a quick indicator of how well positioned emerging nations are to compete in the global economy."

http://www.washingtonpost.com/blogs/ezra-klein/wp/2012/06/24/the-billionaires-list/