Benchmarking the dynamic performance of water companies is a powerful tool to develop sound policies. However, it requires the use of reliable and robust methods and quality of data. In this study, the stochastic nonparametric envelopment of data (StoNED) method was employed to assess productivity change and eco-productivity change of a sample of Chilean water companies over the period 2010–2018. The StoNED approach overcomes the main limitations of stochastic frontier analysis and data envelopment analysis techniques which are the most commonly used to evaluate performance of water companies. Productivity change metric focused on the economic performance, whereas eco-productivity change evaluated economic and quality of service performance by including non-revenue water and unplanned water supply interruptions. Hence, this study analyzed the impact of quality of service variables on the dynamic eco-efficiency of water companies. The annual average productivity change and eco-productivity change estimations were 0.18% and −0.14%, respectively. It was evidenced that on average the Chilean water companies have put as priority to reduce operational costs than to improve quality of service. In both performance metrics, efficiency change was the main contributor to performance changes, whereas the role of technical change was negligible. It was illustrated that full private water companies performed better than concessionary companies and the public company. Reducing non-revenue water and unplanned water supply interruptions was particularly costly for concessionary water companies. The methodology and conclusions of this study are of great interest for water regulators and water utilities to improve the benchmarking process in the provision of drinking water services.

对水务公司的动态绩效进行基准测试是制定合理政策的有力工具。但是，它需要使用可靠和稳健的方法以及数据质量。在本研究中，采用随机非参数包络数据 (StoNED) 方法评估智利水务公司样本在 2010-2018 年期间的生产力变化和生态生产力变化。StoNED 方法克服了随机前沿分析和数据包络分析技术的主要局限性，这些技术最常用于评估水务公司的绩效。生产力变化指标侧重于经济绩效，而生态生产力变化通过包括无收益水和计划外供水中断来评估经济和服务质量绩效。因此，本研究分析了服务质量变量对自来水公司动态生态效率的影响。年平均生产力变化和生态生产力变化估计分别为 0.18% 和 -0.14%。事实证明，平均而言，智利自来水公司将降低运营成本放在首位，而不是提高服务质量。在这两个性能指标中，效率变化是性能变化的主要贡献者，而技术变化的作用可以忽略不计。据说明，完全私营水务公司的表现优于特许公司和公营公司。减少无收益水和计划外供水中断对特许自来水公司来说代价尤其高昂。