Asian countries China and India alternated as the largest economies in the world from 1 AD to about 1800 AD. Prior to World War II, most of Asia was under colonial rule.
Over the years, with rapid economic growth and large trade surplus with the rest of the world, Asia has accumulated over US$4 trillion of foreign exchange reserves - more than half of the world's total.
The economy of Asia comprises more than 4 billion people (60% of the world population), living in 46 different states. Six further states lie partly in Asia, but are considered to belong to another region economically and politically.
As in all world regions, the wealth of Asia differs widely between, and within, states. This is due to its vast size, meaning a huge range of differing cultures, environments, historical ties and government systems.
The largest economies in Asia in terms of nominal GDP are Japan, China, India, and South Korea.
Economies range from Japan, as the world's second largest economy by nominal GDP, to Cambodia as one of the poorest. In terms of GDP by purchasing power parity, China has the largest economy in Asia and the second largest economy in the world, followed by Japan and India as the world's third and fourth largest economies respectively.
Wealth (if measured by GDP per capita) is mostly concentrated in east Asian countries such as Japan and South Korea, as well as in Singapore and in Middle Eastern countries such as Saudi Arabia, Qatar, and United Arab Emirates.
Asia, with the exception of Japan, is currently undergoing rapid growth and industrialization spearheaded by China and India - the two fastest growing major economies in the world.
While east Asian and southeast Asian countries generally rely on manufacturing and trade for growth, countries in the Middle East depend more on the production of commodities, principally oil, for economic growth.
