城市用水的社会成本核算

Social cost accounting of urban water use

城市用水的社会成本是城市社会为用水而直接或间接支付的、以市场价核算的全部成本总和。基于城市用水的生命周期,初步建立城市用水的社会成本核算方法体系框架,将城市用水的社会成本分为取水、制水、供水、排水和污水处理五个部分。以A市为案例的城市用水社会成本定量研究表明,一是A市的城市用水实际投入支出偏低,不足以覆盖相应成本(2015年城市用水供给端的实际投入8 000万元,低于同口径核算成本11 893万元,排放端的实际投入7 000万元,低于同口径核算成本8 183万元)。二是A市城市用水全社会成本至少为6.23元/t,而当地目前实际的居民用水平均价格为2.05元/t,无法体现城市社会为用水而支付的全部成本,难以反映城市水资源的真实价值。三是假定基于社会成本定价,A市居民人均年用水支出占当地居民人均可支配收入的1.2%,完全符合居民承受范围。四是城市用水的社会成本核算方法具有一般可行性,随着成本信息公开制度建立健全,将推动核算更具普适性和准确性。五是城市用水的社会成本核算有助于推动城市用水管理市场化改革,具体体现在推动实现使用者付费、拓展PPP模式应用范围、健全水务市场竞争机制、降低财政支付压力等方面。建议基于社会成本核算制定水价,通过水价真实、客观、显性化地反映城市用水的社会成本;基于社会成本定价改革水务市场运作模式,切实发挥市场在水资源配置中的作用;进一步提高城市用水成本信息公开程度,为水价政策的科学制定和执行监督提供基本保障。

The social cost of urban water use is the full cost paid directly or indirectly for water use by urban society based on market price. According to the life cycle of urban water use, social cost accounting method framework has been established preliminary, in which social cost can be divided into five parts： water intake cost, water making cost, water supply cost, water draining cost and wastewater treatment cost. The case study of city A’s social cost of urban water use shows that： firstly city A’s actual expenditure for water use is not enough to cover the corresponding costs in 2015. 80 million RMB is spent for city A’s water supply, which is less than the same caliber-calculated cost of 118.93 million RMB, and 70 million RMB is spent for city A’s wastewater draining, which is also less than the same caliber-calculated cost of 81.83 million RMB. Secondly, the social cost of urban water use of city A reaches 6.23 RMB/ton at least, while local domestic water price is only 2.05 RMB/ton, which does not cover the full cost urban society pay for water use and cannot reflect the real value of urban water resource. Thirdly, based on social cost pricing, the proportion of per capita annual water use expenditure to per capita disposable income of city A is about 1.2%, which is fully in line with the residents’ tolerance. Fourthly, the accounting method for calculating social cost of urban water use is feasible, and with the improvement of the cost information disclosure system, accounting method will be more universal and accurate. Finally, social cost accounting of urban water use is helpful to market-oriented reform of urban water management, which includes promoting user payment mechanism, expanding PPP mode application scope, perfecting the water market competition mechanism, and reducing the fiscal payment pressure, etc. This paper puts forward following suggestions： making water price based on social cost accounting in order to really, objectively and explicitly reflect the social cost of urban water use in price; reforming the water market operation mode based on social cost pricing to give full play to the role of market in water resources allocation; improving the cost information disclosure of urban water use to ensure the effective supervision scientific formulation of water price policies.