People outside China were generous to rank Beijing one of the 10 most livable cities in China.

An Internet survey of 7,980 people throughout the world voted for 10 cities including Shanghai, Chengdu, Nanjing, Hangzhou and Xi'an. The criteria used to rank the cities are unknown.

Beijing may take encouragement from the result. But it still has a long way to go before becoming a truly livable city.

Most of the nearly 20 million permanent residents in Beijing are too busy living their lives to feel any great need to reflect on its meaning - for the city or them. In a city as diverse as this one, one person's Beijing is likely to be quite different from another's, as is their concept of what makes their part of it "livable" - or not.

The survey did not make clear the complexity of livability. What socio-economic indicators, such as housing affordability, job availability, and hubs of community activity, were included?

Working couples with children are likely to have quite different priorities from the elderly. Even people of similar ages have very different lifestyle preferences. Someone on the urban fringe may delight in the daily birdsong; a CBD resident probably won't mind its absence.

Good public planning must aim to distinguish between an endless list of wants, which reflect people's status and values, and the key needs that should be met in every community. Despite the diversity of community choices, the high cost of property in Beijing means that affordability decides where most people live - only an affluent few have a free choice.

People might have more money and lead more exciting lives in big cities such as Beijing and Shanghai, but they face greater challenges in daily living.

Beijing's museums and historical sites such as the Forbidden City and the Great Wall are enchanting and among the best in the world. But traveling is not easy in Beijing. People need to get used to crowded buses and subways. And the city's air quality is poor for many days of a year.

Still, Beijing should grab this chance to aim big. The city needs to set extraordinary goals.

There are examples of this among the places we think of as "great cities". Copenhagen has the goal of getting 50 percent of its residents to cycle to their place of work or education by 2015. Chicago has the goal of becoming the "most bicycle friendly city in the United States." Portland's goal is to become "the most sustainable city in the world."

The challenge to Beijing's officials is simple: set a challenging target, such as "Beijing will be the most livable city in the World by 2030".

Even if we fall short, no one will have a problem with only being the ninth most livable city in the world.