China's workforce shrinks by nearly 4 million amid greying population
Changing demographics help keep unemployment at bay, but erodes nation's competitiveness

The mainland's working-age population continued to fall last year as Beijing struggled to address a spiralling demographic challenge made worse by its one-child policy.
The mainland's total population stood at 1.37 billion at the end of 2014, according to the National Bureau of Statistics, an increase of 7.1 million on the previous year.
The working-age population, between 16 and 59, fell to 915.8 million last year, down 3.7 million from the end of 2013.
While the shrinking labour pool is helping to prevent a rise in unemployment, it is also driving up labour costs and eroding the manufacturing and export competitiveness that helped fuel China's 30-year expansion.
"It will clearly mean that in the coming 10 years, labour will contribute less to growth than it has done in the last two decades," said Louis Kuijs, Royal Bank of Scotland Group's chief greater China economist.
Yuan Xin , a demographer at Nankai University in Tianjin , said China was unlikely to face an immediate labour shortage.
However, Yuan said, China still faced rising challenges, such as how to improve the quality of its work force to meet the demands of its long-term goals of structural economic reforms.