Chinese statistics have been suspected for long. Recently, the nation's trade statistics were reported to be significantly padded.
Regarding the petroleum statistics, National Bureau of Statistics and General Administration of Customs announce previous month's data on around 10th day of every month. Those figures also have been suspected how reflect real industrial movements since the monthly release timing is too early.
On the other hand, National Development and Reform Commission and Xinhua News are releasing other petroleum related data on after 20th every month.
The below chart compares monthly crude oil processing data released by NBS and NDRC. NBS's data always exceed NDRC's numbers, but the tendency of both figures are similar.
However, the difference between both numbers widened from about 800,000 barrels per day in early 2012 to 1.36 million bpd in December. After that, the difference has shrunk to about 600,000 bpd in May this year. NBS's data in the 4th quarter 2012 seemed to be padded.
Estimated monthly change of crude oil stocks that was calculated based on customs data and NBS's figures is not match with Xinhua News data, as well.
Since statistics data often do not match by the difference in announcement agency in many countries, tendency is more important than each figure. However, no one can trust data that are unsure how sloppy.