DALIAN, China -- The Chinese consumer economy will expand 39% from last year's levels to $6.1 trillion in 2021, fueled by the middle-income population and its diversifying needs, Alibaba Group Holding predicted Wednesday at a World Economic Forum meeting here.

The data comes from joint research by the e-commerce giant's AliResearch think tank and Boston Consulting Group.

The Japanese consumer market is seen growing 18% to $3.3 trillion, meaning that the Chinese market will be nearly twice as large.

The projection assumes annual 5.5% growth in Chinese gross domestic product over five years. Households with monthly income exceeding 12,000 yuan ($1,765) are expected to double to 100 million. These consumers will have a taste for higher-quality goods, according to Alibaba. And much of the rising middle class consists of the internet generation born in the 1980s and later, so e-commerce offers a way to grow sales to Chinese consumers.

Companies offering quality items will see more business opportunities open up in China, AliResearch Dean Gao Hongbing said.

Consumer tastes are increasingly diverse, varying by such factors as generation and gender. New types of demand are seen rising as men spend more on their physical appearance and more people choose environmentally friendly items, for example. In urban centers, singles-oriented products and services are expected to enjoy greater demand as well. Companies need to adapt to this changing market.