Forget the BRICs*.

If you want to get in on the best of the $300-trillion rise in world GDP between now and 2050, you've got to invest in the next set of emerging markets.

Citi economist William Buiter predicts that Nigeria, India and Iraq will be the fastest growing countries from now until 2050, all with over 7.7% in yearly growth. (*India also makes the top ten, outperfoming China, Brazil and Russia to become the world's biggest economy in 2050.)

Meanwhile Western Europe and Japan will languish at sub-2% growth. America will do slightly better.