He appealed on China's rich to "invest in the poor" for their own sake. "Only if we help the poor to rid themselves of illnesses and problems, the entire world can achieve sustainable development," he wrote. 

His appeal in the party paper comes four years after he famously hosted a charity event along with Warren Buffett, the world’s third-richest man, in Beijing.

One-third of a selected group of China’s wealthiest chose not to attend in what observers at the time saw as a lack of interest in philanthropy.

China has the highest number of billionaires in the world after the United States, according to Hurun Report, a media company headquartered in Shanghai. The number of billionaires in China stood at 358 by the end of last year, up by 41 from the previous year.

Yet, Facebook founder Mark Zuckerberg alone donated more than China’s 100 most charitable entrepreneurs combined last year, the Chongqing Morning News noted in a recent commentary.

Most Chinese, wealthy or poor, do not engage in philanthropy, said Scott Kennedy, the director of the Research Centre for Chinese Politics and Business at Indiana University. "This is in part because wealth in China is so new," he said. "It is common globally for large philanthropic giving to occur only once philanthropists become older and start thinking about their legacy."

Coutts, the wealth division of the Royal Bank of Scotland, counted 207 donations worth US$1 million or more in mainland China in 2012, worth a combined US$1.18 billion, in a study released last year. In comparison, it found 1,408 such donations worth a combined US$14 billion in the United States.

China ranked second to last in the World Charity Ranking survey of 135 countries conducted by the Charities Aid Foundation. It measured the percentage of people who donate money, volunteer or have helped a stranger.

With the exception of Hong Kong-based Li Ka-shing Foundation and the Dubai-based Mohammed bin Rashid Al Maktoum Foundation, all of the world’s largest charity foundations are from Western countries.

Gates hence repeated his call in the party paper on Monday today. “China has many successful entrepreneurs and businesspersons,” he wrote. “I hope more insightful people could use their talents to improve the lives of the poor in China and the world.”

There are signs, however, that philanthropy is on the rise in China. Last Thursday, Jack Ma and Joe Tsai, founders of the e-commerce giant Alibaba said they established personal charitable trusts that could be the nation’s largest.

The trusts hold about 2 per cent of Alibaba’s equity, according to a company press release. The fund could be worth between US$2 billion to US$4 billion, after the e-commerce giant’s listing on the New York stock exchange expected later this year.

The new trusts will operate alongside Alibaba’s corporate charitable foundation that has already existed since 2010 and earmarked 0.3 per cent revenue for charity.

“We hope to live in a world with bluer skies, cleaner water and better access to health care,” Jack Ma was quoted in the press release. “We must assume responsibility and take action to improve the environment that our children will inherit.”

No Chinese billionaire has yet signed up to the Giving Pledge, an initiative by Gates and Buffett in which they ask the world’s richest to give at least 50 per cent of their wealth to charity. 

The Chinese government has however gradually been moving toward improving the regulatory environment for philanthropy, said Kennedy. "The key step will be the passage of a Charity Law, which may occur this year," he said. "Once issued, we can expect the overall level of philanthropy to rise rapidly."