摘要
本文通过构建等剩余曲线和Stackelberg-Bertrand博弈模型,分析我国售电市场放开后不同类型售电公司之间的博弈行为和电价的形成机理。研究表明:(1)独立售电公司与寄生售电公司为争取用户而提供相等经济剩余是目前市场出现电价分叉效应的内在原因;(2)寄生售电公司的存在会导致不稳定的市场调整博弈,电价的无规律波动将增加交易成本,阻碍售电公司的市场参与,但发电商为获得更大利润又将促进两类售电公司共存,这为目前独立售电公司不断进入和退出市场的不稳定状态提供了解释;(3)对批发电价进行上限规制,有利于市场形成稳定均衡;(4)售电市场的放开能引导电价的下降,独立售电公司能起到降低电价的作用,同时均衡电价也受到目录电价、固定成本等因素的影响,各因素导致的变动存在一定差异。
China started a new round of power system reform in 2015 namely the power-sale-side reform, which aims to permit social capital to engage in power distribution and sales and enable the electricity selling market to transform from monopoly to a new diversified pattern. One of the purposes is to introduce competition to the electricity retail link, cut down the prices of electricity, reduce the cost of enterprises and thus boost the economic growth. Mainly two types of electricity selling companies were formed after the reform, namely the parasitic companies and the independent companies. The former were originally the marketing department of the electricity suppliers before registered as electricity selling companies. Hence, they can get the electricity at low cost. Actually in the early stage of the reform, their business, finance and many other aspects were still related with their parent companies and their cost still attributed to the parent companies. In theory, their marginal cost can be considered as zero, so they have sheer price advantage in the competition. Relatively, the independent electricity selling companies are invested by social capital and generally don′t have such advantage. Nevertheless, they can offer users diversified value-added services such as energy-saving management, customization, etc. to save their trading cost in purchasing additional power services. By contrast, the parasitic electricity selling companies don′t have the resources and team to provide value-added services. Therefore, the two types of companies have formed their own competitive advantages. Meanwhile, as observed, despite the price advantage of the parasitic companies, some independent companies managed to sign contracts with users at higher prices. That′s to say, the prices of electricity diverge. Besides, the independent electricity selling companies constantly enter and withdraw from the market. In the above context, the paper mainly studies the pricing mechanism of electricity market after the reform to explain the above phenomenon and provide some suggestions for the authorities. After the deregulation of power sale side, the two types of companies purchase the electricity in the wholesale market from the electricity suppliers and then compete to sell it in the retail market. Yet the parasitic electricity selling companies are not completely separated from their parent companies, thus their wholesale price is zero and their earnings also belong to their parent companies. In the meanwhile, the electricity suppliers will decide the wholesale price given to the independent electricity selling companies. Since the power-sale-side reform is still in its early stage, the electricity supplied to the market is still in a seller′s market. Hence, the paper assumes that the wholesale price is unilaterally determined by the electricity suppliers. Accordingly, the current trading process is a typical Stackelberg game. The paper adopts backward induction, firstly analyzing the price game between the two types of electricity selling companies in the retail market and then the optimal wholesale price for the electricity suppliers. Besides, users′ choice of signing contract is seemingly determined by the retail electricity price, however, there are also other factors that influence users′ choice. For instance, independent electricity selling companies offer bundled value-added services to save the transaction cost. Therefore, compared with the standard economic method, the paper puts forward a new method to analyze users′ choice, i.e. users make choices in accordance with the economic surplus provided by the electricity selling companies. Economic surplus refers to the sum of the expected consumer surplus and the trade cost saved after users sign the purchase contract with electricity selling companies. Users will choose the one who offers more economic surplus. The two types of companies will inevitably offer the same economic surplus for the purpose of competing for users, otherwise they will be forced to withdraw from the market. Hence, the paper establishes an equal surplus curve formed by combination of prices of the electricity at which the two types of electricity selling companies can provide users with the same economic surplus, and also studies their price competition based on the equal surplus curve. The findings are as follows. First, the internal cause for diverging price of electricity is that the two types of companies offer the same economic surplus to compete for users. Second, the parasitic electricity selling companies will lead to unstable market adjustment game and the irregular fluctuations in prices will add to the trade cost and hinder the participation for electricity selling companies. Yet the electricity suppliers will promote coexistence of the two types of companies so as to gain greater profits, and as thus the independent electricity selling companies unstably enter or exit the market. Third, price-cap regulation of wholesale electricity prices facilitates the formation of a stable and balanced market. Fourth, the deregulation of electricity retail market will cause the reduction of electricity prices and the independent electricity selling companies are able to play a part in lowering down the prices. Meanwhile, the equilibrium price of electricity is also influenced by tariff, fixed cost and other factors, and there are some differences in the fluctuations caused by the above-mentioned factors.
作者
蒲勇健
高天华
黄毅祥
PU Yongjian;GAO Tianhua;HUANG Yixiang(School of Economics and Business Administration,Chongqing University,Chongqing 400044,China;College of Economics and Management,Northwest A&F University,Xianyang 712100,China)
出处
《管理工程学报》
CSSCI
CSCD
北大核心
2023年第1期158-166,共9页
Journal of Industrial Engineering and Engineering Management
基金
国家自然科学基金资助项目(71673034)
陕西省自然科学基础研究计划(2020JQ-282)
陕西省社会科学基金资助项目(2020R042)。
