The Purchasing Managers' Survey Is a Monthly Survey

 1. Seasonal Adjustment Note: The purchasing managers' survey is a monthly survey, the data of the survey fluctuates very much for the influences of seasonal factors. At present, time series of China's non-manufacturing PMI have met the technical requirements of the seasonal adjustment. The released PMI composite index and sub-indices are seasonally adjusted data. 

2. Explanatory Notes: China non-manufacturing purchasing manager index is composed by 10 sub-indices, i.e. business activity index, new orders index, new export orders index in hand orders index, stock index, intermediate input price index, subscription price index, employment index, supplier delivery time index, and business activities expectation index. Due to the lack of synthesis of non-manufacturing integrated PMI index, the international society often used business activity index to reflect the overall changes in non-manufacturing economic development. The threshold of non-manufacturing PMI is usually using 50 percent as the cut-off point for economic performance. If PMI above 50 percent, it reflects the non-manufacturing economy is expanding; if less than 50 percent, it reflects the non-manufacturing economy is in recession. 

3. Statistical Coverage: The survey involves 27 divisions of non-manufacturing sector in the "Industrial Classification for National Economic Activities" (GB/T4754-2011), and totally 1200 sampling enterprises are selected and surveyed countrywide.

4. Survey Methods: PPS (Probability Proportional to Size) sampling method was adopted in non-manufacturing purchasing managers' survey. Using the divisions of the non-manufacturing sectors as the selecting strata, the sample size of each division is proportional to its proportion of the value-added of the division to the total value-added of the non-manufacturing sector. Within the stratum, the samples are selected according to the probabilities proportional to their principal business revenues of the enterprises. The survey was conducted monthly through Online Reporting System of NBS by sending survey questionnaires to the purchasing managers of the selected enterprises.

5. Calculation Methods: Non-manufacturing purchasing managers survey involves 10 questions on production, new orders (business required), export, existing orders, finished goods inventory, intermediate input price, subscription price, employees, suppliers delivery time, and business activities expectation. Diffusion index was calculated for each question, i.e. percentage of positive answers in number of enterprises plus half of the percentage in the same answers.