Study On Manufacturing PMI Adjustment And Improvement In China

Manufacturing PMI in China has drawn more and more attention since its first publication in July 2005,for that the index can overcome the short-comings such as timing and prediction of GDP and CPI.But the compilation of PMI in China did not happen until recent years.So there are several relevant problems.First of all,PMI consists of 5 diffusion indexes with different weights.And the weight calculation is based on international common weight setting method.But the method was originally made for other countries,not for China.So it is still questionable whether it is reasonable for economic conditions in China.Second,PMI is an index compiled based on the survey for purchasing managers.So it will be influenced by seasonal factors easily.Manufacturing PMI has identical seasonal features even though it has been adjusted seasonally.So it is necessary to find a more effective way to do the seasonal adjustment.This dissertation pointed out the shortage of PMI weight calculation and seasonal adjustment,starting from the compilation of PMI,and tried to present solutions to the problems.Specifically,on weight setting,new weight calculation schemes have been set up regarding 3 aspects including the relationship among PMI and 5 diffusion indexes,the relationship with GDP and with industrial growth rate.Further,the schemes were compared with current non-equal weight method regarding timeliness and prediction ability.The result showed that the weighting scheme considering industrial growth rate works better than the current one.Meanwhile,structural time series model is an effective tool to adjust PMI data seasonally from July 2005 to August 2015.It successfully divided the seasonal factor and achieved fine result.In the end,the possibilities of future PMI weight setting and seasonal adjustment ahead have been presented and suggestions have been made,according to the conclusion of the whole dissertation.