'India to be most populous country by 2025'

India will surpass China as the world's most populous country in 2025, according to projections released by the United States Census Bureau on Tuesday.

The bureau estimates that China's population will peak at slightly less than 1.4 billion in 2026, and begin to decline after that.

The bureau points out that the population growth in China, currently the world's most populous country, is slowing. China's population had reached 1.3 billion in 2006.

While China's population is growing at 0.5 per cent annually, India's population growth is approximately three times higher, at 1.4 per cent. The bureau attributes the difference in the growth rate between the two countries by their respective fertility rates -- the number of births a woman is expected to have in her lifetime.

The Census Bureau estimates that India's fertility rate is currently at 2.7, while China's fertility rate has declined from 2.2 in 1900 to less than 1.6 since 2000.

One of the fall-outs of a declining fertility rate is that the number of new entrants to China's labour force will peak at 124 million in 2010, and decline after that.

India's young labour force, between the age group of 20 and 24, will peak at 116 million in 2024.

"These changes in China's age structure may affect its economic growth and competitiveness in the world market," said Daniel Goodkind, demographer in the Census Bureau's Population Division.

The bureau points out that China and India together account for 37 per cent of the world's total population, and their changing demographic trends will have major implications for population change across the globe.