China passed Japan in 2010 to become the second-largest economy in the world based upon nominal (exchange rate) GDP. China may not pass the United States to become the world’s largest economy until 2030 or later.
In 2019, the IMF has China’s economy at 67% of the size of the US economy and 69% if Hong Kong and Macau are included. The IMF projection for 2024 is for China to reach about 82% of the US economy. If the same rate of catch up is maintained then China (with Hong Kong and Macau) and the USA will be within plus or minus 5% for several years around 2030. This could last from 2029-2037.
From 1999-2010, China moved up from the seventh-largest economy to the second largest. India moved up from the 13th largest to ninth largest. There were more shifts with the far stronger economic growth in Asia and China’s double-digit growth.
There is far slower movement in economic power now with strong economies growing at 5-7% per year GDP growth and slower growing developed economies at 1-3% per year GDP growth.
India will have moved up from the 9th largest economy to the 5th largest economy. India should become the fifth-largest economy on an exchange rate basis at the end of 2019. It will then take another 5-7 years for India to pass Germany for fourth and then another few years to pass Japan for third.
India and China have both had their economic statistics called into question. Both may be overestimating their GDP by 10-25%.
It is taking many years for small moves up the rankings of the largest national economies.
Brazil is edging up slightly ahead of Italy. South Korea, Indonesia, Singapore, Vietnam and the Philippines are moving up the global economic rankings. Indonesia and the other ASEAN countries are fairly consistently reaching 5-7% per year GDP growth. Ethiopia is moving up as well.
The static nature of the future world economy could shift if some countries are able to adopt new fast-growing technologies like self-driving cars, anti-aging, nanotechnology and AI and other countries fall behind.