"I helped a social worker who was raising money for an NGO. I promised her I would give a balloon performance, though I only knew the basics, from reading numerous books," he said.

Chan has continued to master the art.

"Besides bringing happiness to others, balloons can be a type of emotionally focused therapy," he said. "For some people, like those who are in hospital or under immense psychological pressure, this little thing can quell their emotions."

Chan, an MTR Corporation technician by day, is one of the just 14 per cent of Hongkongers who engaged in volunteer work in the last 12 months. This is a much lower proportion than in most Western countries, or in Asian neighbours such as Japan and Taiwan, according to research from the University of Hong Kong.

It's a disappointing figure, given international research showing that volunteering can benefit the physical and mental health of the volunteer, as well as society at large.

For Chan - who has at times put in 20 hours a week working for the Agency for Volunteer Service and five other groups - the satisfaction of volunteering is worth more than the HK$400 he could earn for giving a three-hour balloon-art lesson.

"I can make a lot of money, but cannot get the satisfaction and happiness that I get from the volunteer training," he said.

"I can only train two to six good volunteers at once. But if I run six courses at a time, then I may end up with 36 new volunteers. And don't forget, they will motivate others as well."

Most people who join his courses are initially more interested in learning how to do wonderful things with balloons, rather than volunteering. So in the first four sessions of the 10-part course, he teaches students what balloon art is. Then in the following six weeks, he infuses the eight elements of volunteering - which he says are modesty, love, compassion, sincerity, understanding, respect, consideration and tolerance.

Dicky Ip Ka-hoi, a computer maintenance worker, is one of those inspired by Chan.

"There is a lot of demand for his skills, both his balloon-tying skills and his volunteering skills," Ip said. He has been learning from Chan for two years and now performs for elderly people, children and groups such as the eye-health charity Orbis.

But a two-year study into family harmony and social cohesion released last month by HKU's school of public health shows that Chan and Ip remain in the minority.

Some 46 per cent of Canadians and 36 per cent of Australians said they had volunteered recently, while in Japan and Taiwan the rates were 28 per cent and 19 per cent respectively.

"In viewing social capital, foreign countries usually look at the participation rate of volunteers, as they can directly help certain sectors of society," said Professor Gabriel Leung, HKU's head of community medicine. He agrees that the practice of volunteering in Hong Kong is not as mature as it is in Western countries.

A similar picture emerges from the 2012 World Giving Index, a ranking of charitable activity prepared by the British-based Charities Aid Foundation. Hong Kong ranked 19th worldwide, and was the most generous place of the six surveyed in East Asia in terms of cash donations. But it ranked second worst in the region for volunteering time. Only the mainland ranked lower.

But volunteer groups say the surveys may not show the full picture. While formal volunteering - through a group or NGO - is easy to quantify, informal volunteering - which can be as simple as helping an elderly neighbour with the shopping - is much harder to measure.

"In Chinese culture, we emphasise mutual help and care. But many of us do not do volunteer work through organisations," said Flora Chung Woon-fan, CEO of the Agency for Volunteer Service. She points out that the World Giving Index found that Hongkongers were the most likely in the region to volunteer to help a stranger, at 56 per cent.

Chung says many Hongkongers who volunteer lack a clear perception of what volunteering is. They may say in a survey that they do no volunteer work, when in fact they do.

"Many people in Hong Kong have given voluntary services but they are not aware of it," she said. "They may be board members on some NGOs, but they do not know that this is a kind of voluntary service, as they think volunteering must be helping elderly people.

"This may explain why we have a lower participation rate than Western countries."

People working in the 300 advisory committees in the government, and social activists in the culture, sport, and political sectors, were all volunteers, she added.

Euphen Wong Yeuk-ting, 36, used to work as a landscape designer. She said she knew she was volunteering when she acted as the landscape consultant to the conservation committee at Maryknoll Convent School, which required her to attend quarterly meetings and review the condition of trees on campus.

But she has doubts about whether her latest project, helping dog owners near her home in Mei Foo, counts as volunteering.

"The neighbourhood in Mei Foo has asked me to see which spot in the district is suitable for a dog park, as there are too many dogs there," Wong said. "I have spent a week setting up a group on Facebook to get in contact with dog owners and volunteers, but I have not registered with any formal organisation." She also completed a proposal for the dog park after doing some landscape analysis.

Chung says that what defines volunteers is that they take action, unpaid, of their own free will to benefit others.

And she points to separate research by HKU's Centre for Civil Society and Governance, which showed that the volunteering rate went up from 12 per cent in 2001 to 19 per cent in 2009.

Chung says Western countries have a deeply ingrained volunteering culture. High unemployment in countries such as Britain also means that people turn to volunteering to pick up skills they hope will help them find work.

Chung says that what Hong Kong has is potential.

"Our participation rate is not saturated yet, while it has remained at 40-something per cent in Canada. It won't get any higher there, but we have the potential to do more."

There is also good news from corporations in the city. They are taking a more active role in encouraging volunteering, to polish their image and fulfil their social responsibilities.

For example, Swire Properties started its Community Ambassador Programme in 2001. It is a volunteer programme led and driven by employees, who help the needy in Hong Kong and the mainland, with a focus on environmental protection, education initiatives and the promotion of the arts and culture.

"The programme has grown to include nearly 1,300 ambassadors," a Swire spokesman said.

In another example, since 2006 Swire's "Mr Fix-It" programme has seen members of its technical staff offer home maintenance and minor renovation work to elderly people, such as repainting walls and repairing broken tiles.

"There are many types of volunteers. Some mainly provide their time, while some provide their talents and expertise, like volunteer Chinese medicine practitioners and legal consultants," Chung said.

The study by the Centre for Civil Society and Governance shows that volunteers tend to be younger, better educated people with higher incomes. Younger volunteers, often students, may do voluntary work to gain school credit, but often continue to volunteer later in life, Chung says.

Chan, the balloon artist, agrees. He's planning to train volunteers at secondary schools.

"I want them to know the real meaning of volunteering, to learn to communicate and understand others' feelings. This can help them reflect on their lives."