基于地区相似性判断的购买力平价指数研究

The Research of Purchasing Power Parity Based on the Judgment of Regional Similarity

地区购买力平价是世界银行推荐的一个重要指数,用于反映地区价格差异和经济发展不平衡程度。目前学术界构建购买力平价指数并未充分考虑地区相似性特征。尝试改进依据最短路径判断地区相似性的方法可以提升地区购买力平价结果的可靠性。改进体现在突破以往只选择一个地区为基准地区并寻找最短路径的做法,尝试将考察的任何一个地区依次设为基准地区,并加入对地区相似性程度的量化分析,进行综合的最短路径探索,由此判断出最为相似的地区。研究结论如下:多基准地区最短路径法得到的地区购买力平价数值更加接近现实,这解决了传统文献往往只选择一个特定基准地区确定最短路径引起的结果不确定的缺陷;多基准地区最短路径法形成地区相似性矩阵,根据加权GEKS指数(Weighted Gini-Elteto-Koves-Szulc Index)链接双边比较指数得到最终结果,这突破了传统最短路径法仅仅使用GEKS指数引起的可靠性弱的缺陷;加权GEKS法中地区相似性权重对GEKS指数具有明显的修正作用,并且对国内地区东、中、西部的影响程度不同。

Sub-national purchasing power parity(PPP)is an important index recommended by the World Bank to reflect regional price differences and imbalances in economic development.At present,academia has not paid enough attention to regional similarity.It attempts to improve the method of judging regional similarity based on the shortest path to improve the reliability of regional purchasing power parity(PPP).The improvement of the shortest path method lies in breaking through the previous practice of choosing only one area as base.It attempts to set any area under investigation as the base area in turn,add quantitative analysis of regional similarity degree.The conclusions are as follows,the results of the shortest path method of multi-datum area are closer to the reality.It also solves the disadvantages of uncertain results caused by the fact that traditional literature which only chooses a specific base area to determine the shortest path.The shortest path method of multi-datum area can produce regional similarity matrix,and link the bilateral comparison index according to the weighted GEKS index to get the final result.It breaks through the traditional shortest path method which only uses GEKS method to transform exponentially,whose results are in weak reliability.The weight of regional similarity in weighted GEKS method has an obvious correction effect on the GEKS index,and it has different influences on the eastern,central and western regions in China.