EMPIRICAL RESEARCH ON CACULATING "BASIC SECTOR" OF BEIJING——BASED ON LOCATION QUOTIENTS TECHNIQUE AND INPUT-OUTPUT ANALYSIS
以北京为例，利用投入产出表计算各行业净出口作为基础部门的真实值，发现传统区位商技术误差很大，因此提出改进公式并通过多年数据验证，显著降低了误差。
The local economy can be divided into two very general categories: basic sector and non-basic sector. The basic sector is identified as the engine of the local economy and the key to economic growth and prosperity. So it is very important and useful to distinguish between basic sector and non-basic sector. The location quotients technique is one of the most frequently used tools to calculate basic sector in economic geography and local regional economic analysis. In this paper, taking Beijing as an example, based on the input-output table of Beijing and the input-output table of China, the net export of every industry is calculated to represent the basic sector, and regarded as corresponding correct value. First of all, we calculate basic sector with the traditional location quotients technique. Comparing the results with correct value, very great errors between them are found. So, in the paper, the traditional location quotients technique has been improved. Based on the theoretical formula for the relationship between basic sector and location quotient under the traditional location quotients technique, we have put forward four alternate formulae available. Through the validation of these four formulae with many years' real data of Beijing, we have confirmed the best formula of the improved location quotients technique. Then according to the formula, the basic sector and the errors of Beijing for many years is calculated. Compared with the errors under the traditional location quotients technique, the errors reduce obviously. It proves that the improved location quotients technique is valid. In addition, a new regression formula based on the rate of Intermediate use which can be used to calculate basic sector has been derived. According to the equation, the basic sector and the errors of Beijing for many years are calculated. Compared with the errors under the traditional location quotients technique, the errors reduce obviously too.