Brunei topped the list of Asia's richest economies by per capita income and Hong Kong emerged as the biggest spender, according to a study released Monday.
Nepal, meanwhile, was the region's poorest by both measures.
The report by regional statistical agencies, coordinated by the Asian Development Bank, showed wide disparities in Asia's living standards.
It found that the tiny, oil-rich sultanate of Brunei has a per capita gross domestic product 13 times higher than the regional average of 20,432 Hong Kong dollars (US$2,621; ??1,789), and more than 40 times larger than the lowest-ranked Nepal.
Brunei is followed by Singapore, Macau, Hong Kong and Taiwan. Apart from Nepal, the poorest have-nots include Bangladesh, Cambodia, Laos and India.
The study covered 23 economies, excluding Japan, South Korea and East Timor.
India, one of the world's fastest growing economies, has a per capita income of 12,090 Hong Kong dollars (US$1,551; ??1,059), still behind the regional average and also below Sri Lanka and Pakistan.
China, meanwhile, ranked above average with its per capita income of 23,267 Hong Kong dollars (US$2,986; ??2,038).
Meanwhile, Hong Kong residents were the biggest spenders, according to a measure of household living standards called the per capita actual final consumption expenditure index. Taiwan and Brunei came in second and third.
In terms of spending, China and India both lagged behind the regional average, the study found.
"The study shows the growth and developmental challenges facing the region," said Ifzal Ali, ADB's chief economist. "The region has miles to go before celebrating its economic success."
The study, called "2005 International Comparison Program in Asia and the Pacific: Purchasing Power Parity and Real Expenditure," is part of a global initiative spearheaded by the World Bank that allows cross-country comparison of purchasing powers of currencies and living standards.
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