China?s sixth national population census, the results of which were announced last month, offers a comprehensive series of statistics about the country?s demographic trends over the last decade?think India?s 15th census of 2011. The results capture important changes in population growth. China?s population has grown from 1.27 billion in 2000 to 1.34 billion in 2010. This is an increase of 5.8%, and the slowest rate of growth in nearly half a century. India?s population has surged to 1.2 billion in 2011, an increase of 181 million since 2001. India?s population has also registered slower growth?a decrease of 3.9% compared with 2000-2010. It is estimated that India will overtake China as the world?s most populous nation in 2030. For now, India and China together represent 37% of the world population.

China?s census results broadly confirm and substantiate what are, by now, well-known facts: China?s transition from a peasant, rural economy with low levels of education, burdened by an immobile labour force (due to hukou or household registration) to an increasingly mobile economy with 221 million on the move (living outside their native place). Half of the Chinese now live in cities. Compared to 2000, the university educated populace has increased by 2.5 times. NYT quoted Wang Feng, head of the Brookings-Tsinghua Centre for Public Policy at Tsinghua University in Beijing as saying that China ?has completely turned a page in its demographic history?. The changes confirm the momentous impact of Deng Xiaoping?s economic reforms of 1978.

The current census exercise was a gargantuan one, which engaged an estimated six million census takers who surveyed 400 million households. An important trend in China?of people being on the move?was captured via an unprecedented break with past practice, by counting people where they actually lived instead of where their hukou was registered, in order to get a more accurate picture of population mobility.

Thus far, China?s notorious hukou system (an invention of socialist China that was promulgated in 1958) ties citizens (either rural or urban) to their places of birth, thereby restricting population mobility. In rural areas, citizens have an agricultural hukou; in other areas, citizens have a non-agricultural hukou. Deng?s reforms relaxed hukou strictures, enabling and unleashing the largest internal migration in history. Hukou still plays an important role despite relaxation; and, in the last decade, hukou reform has been the point of contention. Still, China?s mobile population has been swelling. There is a five-fold increase from 40 million in 1990 to 221.4 million today, with ?mobile? defined as those who have left the locality of their registered address for more than six months.

A second trend that is equally dramatic is that China?s urban population has doubled in two decades. Today, half of China lives in cities, up from 36% in 2000. In comparison, 28% of Indians lived in urban areas in 2000, and that number has shot up to 35% in 2011.

Both China and India have cause to cheer from rising literacy. Literacy has shot up to 74% in India today.

China?s literacy is now at 92%, with 8.9 citizens per hundred having attended university.

While India?s demographic dividend is seen as an opportunity, the writing on the wall is clearly the reverse for China. Its past policies have led to three major trends that have now sparked a national debate: slow population growth, restrictive family planning and shrinking family size, and a greying population.

The ?one-child? policy underlies shrinking families, with the average family size dropping from 3.44 in 2000 to 3.1 in 2010. As nuclear families have been increasing and fertility rates decreasing, sinologists have been noting with alarm the ?little emperor? phenomenon. Sociologist Elizabeth Croll calls it the 4:2:1 or six pockets-one child syndrome: of two parents and four grandparents and one child.

As for graying, China?s under-15 population has dropped by a sharp 6.29%, while the over-60 population has increased by 2.93%. In comparison, India is a young country, with children representing one-fifth of the population. India also has the largest proportion of people in the world in younger age groups. In China, 16.60% of the population is in the 0-14 age group. In comparison, an estimated 29% are in the 0-14 age group in India.

In China, people aged 60 or more account for 13.26% of the total, those aged 65 and above account for 8.87%. Both these figures are significantly lower in India. Thus, India is talking of a ?demographic dividend??which economist Pranab Bardhan has warned could be more hypothetical than real, given the lack of productive employment and education. Wendy Dobson has also indicated that India?s under-use of its labour force is its Achilles? heel.

China is looking at a shrinking labour market. It is predicted that its working age population will start contracting in 2015, and experience negative growth around 2020. China?s ageing population also calls for renewed efforts to strengthen the existing social safety net.

Unlike India?s latest census, which shows the worst sex ratio since Independence, China?s gender ratio appears to be the most balanced since 1953. However, the census also indicates the country?s continued preference for male offspring?there are now 118 males for every 100 females.

A trend that has been widely publicised in the Chinese press is the higher growth rate of the minority nationality population (who are free from the constraints of the ?one-child? policy), growing from 8.41% in 2000 to 8.49% of the population in 2010. There is a need to exercise some caution in interpreting this, as individuals in China can ask for a change in ethnic status if they are ?one quarter minority? (have a parent or grandparent who is from an ethnic minority). Many Chinese would admit to greasing palms to shift ethnic identification, which is somewhat akin to wanting to be classified OBC or SC/ST in India.

For China, the census has come at an opportune time, for the leadership-in-waiting to reassess policy prescriptions to normalise the sex ratio, rethink family planning, speed up social insurance and hukou reform, and build urban infrastructure. China confronts the unprecedented historical reality of getting old before it gets rich, which will have huge implications for a billion plus people. These will be the challenges that the duo of Xi Jinping-Li Keqiang (President-Premier in waiting) will inherit at the 18th Party Congress scheduled in 2012.

The author is a sinologist based in Singapore, and she is currently Visiting Fellow at the Institute of Chinese Studies, DelhiViews are personal