According to the National Bureau of Statistics, in the first quarter of 2012, the total national GDP in China was 10,800 billion RMB, while the total of all local GDP amounts was 11,280 billion RMB for the same period. The difference is 480 Billion RMB (US $75.65 billion). China Economy reporters calculated the total through a summation of the local numbers. Every year since 1985, when local and national governments started to calculate GDP separately, the two numbers have been inconsistent. While different methodologies may have contributed to the inconsistency, the authorities believe that data fraud has been a cause. According to the National Bureau of Statistics, despite government efforts to curb fraud, local governments frequently use their administrative power to arbitrarily adjust the GDP number upward to demonstrate their achievements and competence.
Source: China Economy reprinted by Xinhua, May 24, 2012
http://news.xinhuanet.com/fortune/2012-05/24/c_123184185.htm