According to a YouTube presentation , PriceWaterhouseCoopers predicts that by 2050, the world's top 10 largest economies by GDP in nominal terms (denominated in trillion US dollars) will be as follows –

• No. 1 – China (50)
• No. 2 – USA (34)
• No. 3 – India (28)
• No. 4 – Indonesia (7.3)
• No. 5 – Japan (6.8)
• No. 6 – Brazil (6.5)
• No. 7 – Germany (6.1)
• No. 8 – Mexico (5.6)
• No. 9 – United Kingdom (5.4)
• No.10 – Russia (5.1) 

This forecast means that by 2050, 

• China's economy will be almost 1.5 times larger than the United States as number 2 and almost 10 times the UK as number 9.
• China plus India's will be larger than the rest of the top ten economies combined. 
• The size of Indonesia's economy will leapfrog from the 16th position today to the 4th, while Mexico will jump from the 15th to the 8th.
• China with the rest of the developing top ten will be 86% larger than the Western top ten combined (excluding Russia). 

These numbers suggest that dynamics are already set in motion shaping a tectonic shift of world power by mid-century.