NEW DELHI: China's ageing population will erode its economic growth potential in the long term, should policy measures fail to boost the birth rate, raise productivity via technological progress and shift its industrial strategy to mitigate the supply and demand imbalance, global ratings agency Moody's Investors Service said in a report on Thursday. "Barring gains in productivity, the decline in labour supply and increased healthcare and social spending could lead to a wider fiscal deficit and higher debt burden," the report said.China is already grappling with slowing growth,...