世界银行低估发展中国家的购买力平价吗——基于修正的巴拉萨-萨缪尔森效应的测度研究

Does World Bank Underestimate the Purchasing Power Parities in Developing Countries? A Measurement Study Based on Modified Balassa-Samuelson Effect

世界银行于2014年公布了2011年全球国际比较项目(ICP)中所有国家的购买力平价数据,以及经购买力平价转换后的各国GDP。数据显示,发展中国家的经济总量较转换前大幅度上升。这引发发展中国家的购买力平价是否被系统性低估的疑问。在深入分析现有测度购买力平价偏差的文献不足的基础上,基于修正的巴拉萨-萨缪尔森效应理论,以欧盟-OECD为参照系,构建了一种测度不发达地区购买力平价偏差的方法。测度结果显示:亚太、非洲及西亚地区的购买力平价被系统性低估约30%,从而导致以购买力平价为货币转换因子计算得出的这些地区和国家的经济总量被严重高估。基础价格数据质量较低、规格品代表性和可比性的难以协调以及购买力平价全球汇总方法中支出权重的影响是导致不发达地区购买力平价被低估的主要原因。

World bank published in 2014 the purchasing power parities data of all the countries in the 2011 round of ICP and each country＇s GDP converted by purchasing power parities. The data shows that the economic aggregate of the developing countries rose sharply compared with that before converted, which raised some doubts about whether their purchasing power parities are systematically underestimated.Through an in-depth analysis of the existing literatures on the measurement of the purchasing power parities bias which are not sufficient, this paper works out a method to measure the purchasing power parities bias at the underdeveloped area by taking EU-OECD as a reference system and on the basis of the modified BS effect theory. The results show that the purchasing power parities in Asia-Pacific,Africa and west Asia are systematically underestimated by 30%, so that the economic aggregate of these areas is overestimated heavily, which is calculated with the purchasing power parities as a currency conversion factor.The main reasons for the underestimation of the purchasing power parities in the underdeveloped areas are the following： the lower quality of the basic price data, the difficult coordination between the representativeness and comparability of the standard products, and the influence of the expenditure weights in the global aggregation method of the purchasing power parities.