Departamento de Ingeniería Hidráulica y Ambiental, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna, 4860, Santiago, Chile.
Escuela de Arquitectura e Instituto de Estudios Urbanos, Pontificia Universidad Católica de Chile, El Comendador, 1916, Santiago, Chile.
Environ Sci Pollut Res Int. 2017 Jul;24(20):16994-17005. doi: 10.1007/s11356-017-9345-2. Epub 2017 Jun 3.
The assessment of productivity change over time and its drivers is of great significance for water companies and regulators when setting urban water tariffs. This issue is even more relevant in privatized water industries, such as those in England and Wales, where the price-cap regulation is adopted. In this paper, an input-distance function is used to estimate productivity change and its determinants for the English and Welsh water-only companies (WoCs) over the period of 1993-2009. The impacts of several exogenous variables on companies' efficiencies are also explored. From a policy perspective, this study describes how regulators can use this type of modeling and results to calculate illustrative X factors for the WoCs. The results indicate that the 1994 and 1999 price reviews stimulated technical change, and there were small efficiency gains. However, the 2004 price review did not accelerate efficiency change or improve technical change. The results also indicated that during the whole period of study, the excessive scale of the WoCs contributed negatively to productivity growth. On average, WoCs reported relatively high efficiency levels, which suggests that they had already been investing in technologies that reduce long-term input requirements with respect to exogenous and service-quality variables. Finally, an average WoC needs to improve its productivity toward that of the best company by 1.58%. The methodology and results of this study are of great interest to both regulators and water-company managers for evaluating the effectiveness of regulation and making informed decisions.
随着时间推移评估生产力变化及其驱动因素对于水务公司和监管机构制定城市水价具有重要意义。在采用价格上限监管的英国和威尔士等私有化水务行业，这个问题更加重要。本文使用投入距离函数来估计 1993-2009 年期间英国和威尔士的纯水务公司（WoC）的生产力变化及其决定因素。还探讨了几个外生变量对公司效率的影响。从政策角度来看，本研究描述了监管机构如何利用这种类型的建模和结果来计算 WoC 的说明性 X 因素。结果表明，1994 年和 1999 年的价格审查刺激了技术变革，效率略有提高。然而，2004 年的价格审查并没有加速效率变化或改善技术变革。结果还表明，在整个研究期间，WoC 的过度规模对生产力增长产生负面影响。平均而言，WoC 报告了相对较高的效率水平，这表明它们已经在投资于技术，这些技术减少了与外生和服务质量变量相关的长期投入需求。最后，平均 WoC 需要将其生产力提高到最佳公司的 1.58%。该研究的方法和结果对于监管机构和水务公司管理者评估监管效果和做出明智决策都具有重要意义。
