市场竞争与价格离散——影响机理与经验证据

doi:10.16381/j.cnki.issn1003-207x.2018.11.009

摘要/Abstract

摘要： 价格离散背离了"一价定律"，是市场运行效率低的一种反映，但却是一种普遍存在的现象。那么，通过市场竞争机制能否降低某一行业（产品）的市场中的价格离散?本文先是分别在消费者信息搜寻理论和厂商空间竞争理论的框架下，分析市场竞争对价格离散的影响机理。然后，本文收集了我国地级（及以上）城市的车险市场上所有企业的价格和其他相关变量，研究主要发现：即使去除了产品异质性，车险市场仍然存在明显的价格离散，企业之间价格的变异系数的均值和中位数分别为0.472和0.445；市场竞争能够降低车险市场的价格离散，平均而言，企业数目提高10家（市场集中程度降低一单位样本标准差），企业之间车险价格的标准差将降低其平均水平的约25%（5%~6%）。辅助性分析和稳健性分析支持了本文结论。本文的政策含义在于：应当增进供给侧的竞争，降低需求侧的信息搜寻成本。

关键词: 市场竞争, 价格离散, 信息搜寻, 空间竞争, 保险

Abstract: Price dispersion refers to the phenomenon that the same good is sold at different prices at the same time in a given market. Price dispersion violates the "law of one price" and reveals the low efficiency of market running, however, price dispersion is a universal phenomenon. Can market competition reduces price dispersion in an industry (or product)? Few literatures have formally studied this topic in the Chinese market. Firstly, the effect mechanism, results and conditions of competition on price dispersion are demenstrated by mathematical model under the framework of consumer information search theory and firm spatial competition theory, respectively. Then, the data of price and relevant variables of all the car insurance firm for about 300 prefecture-level cities during 2005-2014 are collected, in consideration of the several advantages of Chinese insurance market data. Using the statistical description of related indicators and regression analysis in multiple dimensions, it is mainly found that that even eliminating the product heterogeneity, apparent price dispersion lies in car insurance market, and the mean and median of the coefficient of variation for the price is 0.472 and 0.445, respectively. Market competition can reduce price dispersion among firms in the car insurance market. The number of car insurance firm increases by ten (the market concentration ratio decrease by one standard deviation in the sample) can decrease the standard deviation of car insurance price by about 25 percent (5 percent-6 percent) of its sample's average level, as a whole. The results are robust to static and dynamic panel data econometric models, to several price dispersion indices, to the majority of indices measuring competition, and to several subgroup analysis. The methods of this paper can be referenced to study the relationship between market characteristics and price dispersion in other fields. The policy implication of this paper is that to improve the efficiency of market running, the policy makers should enhance competition among the supply side and reduce search costs of the demand side. Finally, this papers' limitations and further research directions are put forward from the aspects of the research hypothesis, sample characteristics and new topics.

Key words: market competition, price dispersion, information search, spatial competition, insurance

中图分类号:

王向楠. 市场竞争与价格离散——影响机理与经验证据[J]. 中国管理科学, 2018, 26(11): 83-93.

WANG Xiang-nan. Market Competition and Price Dispersion-Effect Mechanism and Empirical Evidence[J]. Chinese Journal of Management Science, 2018, 26(11): 83-93.

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