China's working-age population, that is people aged from 15 to 59, registered a rare and worrying decline in 2012, decreasing by 3.45 million to 937 million, according to the National Bureau of Statistics. The proportion in the total population shrinking by 0.6 percentage points to 69.2 percent. This is worrying as the NBS predicts the decline will continue to 2030.

This demographic change means China's sustainable economic growth will gradually lose two favorable conditions: the absolute advantage of labor supply and the comparative advantage of cheap labor. Considering most people are retired at the age of 60 in China, the decline in the number of people aged from 15 to 59 will affect the economy and aggravate the country's labor shortage.

Distinguishing between the working-age population, labor force and employed population will be helpful when interpreting the economic impact of a declining working-age population.