By Kam Wing Chan
Kam Wing Chan, professor of geography at the University of Washington, is an expert on Chinese population statistics and is a guest contributor to the Dragonbeat blog this week.
How big are Chinese cities? That depends on how you measure them.
Back in 2005, Time magazine proclaimed that Chongqing had become “the largest city not only in China but in the world”, with a population in excess of 30m.
But any Chinese citizen will tell you that Beijing and Shanghai, both with real urban populations below 15m, are larger than their supposed competitor in China’s southwest.
Common confusion over the true population size of Chongqing and other Chinese cities reflects the fact that China has highly complex and confusing urban and city statistical data.
Confusion over urban population sizes arises because the boundaries of large Chinese cities typically encompass an urbanised core surrounded by numerous scattered towns and large stretches of rural territory, usually with dense farming populations.
These cities are so large in area that they are more aptly called regions. Chongqing, which has an administrative area roughly the size of Austria, is the most extreme example.
Chongqing’s official population of 32m does not represent the true metropolitan population because more than two-thirds of the employed workers in the so-called municipality are actually engaged in agriculture.
There are two main ways to define urban areas in China: by administrative boundaries or by objective criteria such as the density of population and buildings. In Chinese cities, administrative boundaries and objectively urbanised zones overlap, often confusingly.
A Chinese municipality comprises two types of administrative jurisdictions, “city districts” (shiqu) and counties (xian). Typically, most of the shiqu are objectively urbanised. The counties are mostly rural but may contain urbanised pockets, often referred to as “towns”.
The situation is complicated further by the important official distinction between two groups of individual Chinese citizens, those with local residence permits, or hukou, and those without.
Although population statistics based on the number of local hukou holders are issued every year and are widely available, they do not show the actual population of cities. But the numbers are often mistakenly used as such.
For almost all major cities, the registered population is smaller than the actual population, which includes migrants whose hukou remains back in their original community. In some cases the difference is huge: the gap between the registered and actual population in the migrant city of Shenzhen, for example, was 6.3m in 2005.
Different statistical approaches to calculating urban populations matter because they can have a huge impact on economic planning and investment decisions. Numerous studies comparing the competitiveness or productivity of cities in China have used the wrong city population numbers to generate per capita GDP and other measures.
Many have applied the hukou population to compute per capita urban GDP, unaware that this population statistic does not encompass all city residents and in some cases may include only a minority of the true population.
Despite attempts by China’s National Bureau of Statistics to solve the problem, individual city population numbers remain a statistical minefield for foreign businessmen chasing the elusive Chinese consumer.
The result is that China’s population statistics and per capita GDP figures both come with a severe health warning.