Eco-efficiency assessment under natural and managerial disposability: an empirical application for Chilean water companies.
Getting a good understanding regarding the economic and environmental performance of water utilities is of great importance to achieve the goal of an efficient and sustainable industry. In this study, we apply the range adjusted measure (RAM) data envelopment analysis (DEA) model to evaluate the integrated (production and environmental) efficiency of several water utilities located in Chile. Integrated efficiency is evaluated using the concepts of natural and managerial disposability. This approach further allows us to quantify the contribution of each input and undesirable product on efficiency scores. The results highlighted that the Chilean water industry showed high levels of production…
Carbon efficiency analysis in the provision of drinking water : Estimation of optimal greenhouse gas emissions
Producción Científica
Comparing changes in productivity among private water companies integrating quality of service: A metafrontier approach
Abstract Most previous studies evaluating the effect of ownership on the performance of water companies have ignored the fact that there are several types of private water companies. In this study, we instead recognize that private water companies can differ considerably in how they are managed, based on whether their infrastructure is privately or publicly owned. We estimated change in productivity of fully-privatized companies and concessionary companies by employing the metafrontier Malmquist Luenberger productivity (MMLP) index, which allowed us to integrate quality-of-service variables as undesirable outputs. We segregated the MMLP index to assess changes over time in relative efficien…
Marginal abatement cost of carbon dioxide emissions in the provision of urban drinking water
Abstract Reducing greenhouse gas emissions is a major challenge faced by cities seeking to improve their environmental sustainability. Doing so requires a good understanding of the costs associated with lowering emissions and factors that may influence this cost. This study estimated the marginal abatement cost of reducing both direct and indirect CO2 emissions in the provision of drinking water by several water companies in England and Wales. The results indicated that during the years 2013–2018, the average cost to the English and Welsh water industry to prevent 1 kg of CO2 emissions was 0.264₤ which was equivalent to 61% of the price of the delivered drinking water The results of the Mor…
Productivity growth of wastewater treatment plants – accounting for environmental impacts: a Malmquist-Luenberger index approach
As the number of wastewater treatment plants (WWTPs) has increased, the economic considerations associated with their management have become more relevant. Measuring the productivity of WWTPs allows the best practice to be identified and resource use to be optimized. Previous studies assessing the productivity change of WWTPs have ignored undesirable outputs; thus, wastewater treatment was considered to be free of environmental impacts. To overcome this limitation and for the first time, we assessed the productivity growth of a sample of Spanish WWTPs, while also accounting for the emission of greenhouse gases and sludge production. The Malmquist-Luenberger productivity index (MLPI) and its…
Water company productivity change: A disaggregated approach accounting for changes in inputs and outputs
Abstract The assessment of the productivity change of water utilities provides essential information to sector managers and regulators. This study uses the Luenberger-Hicks-Moorsteen Productivity Indicator (LHMPI) to evaluate productivity change as it can be further decomposed into three components namely technical change (TC), technical efficiency change (TEC), and scale efficiency change (SEC). This study evaluates the productivity of several water companies in England and Wales from 2001 to 2018. We found that productivity declined 1.2% per year due to the use of inputs that increased by 1.4% per year relative to outputs that increased by 0.2% per year.
Economic and environmental performance of wastewater treatment plants: Potential reductions in greenhouse gases emissions
Abstract Sanitation and wastewater treatment are essential for protecting human health and environmental sustainability. Treatment processes are not free of environmental impacts; consequently assessment of the environmental performance of wastewater treatment plants (WWTPs) has gained interest in recent years. Unlike other methods, a direct approach is followed to estimate environmental performance indicators (EPIs) using data envelopment analysis (DEA), i.e. an index of overall performance is directly obtained. The present study represents pioneering work to integrate environmental impacts in the assessment of the efficiency of WWTP estimating pure (PEPI) and mixed (MEPI) environmental pe…
A management and optimisation model for water supply planning in water deficit areas
Summary The integrated water resources management approach has proven to be a suitable option for efficient, equitable and sustainable water management. In water-poor regions experiencing acute and/or chronic shortages, optimisation techniques are a useful tool for supporting the decision process of water allocation. In order to maximise the value of water use, an optimisation model was developed which involves multiple supply sources (conventional and non-conventional) and multiple users. Penalties, representing monetary losses in the event of an unfulfilled water demand, have been incorporated into the objective function. This model represents a novel approach which considers water distri…
Understanding water energy nexus in drinking water provision: an eco-efficiency assessment of water companies
Producción Científica
Eco-Efficiency of the English and Welsh Water Companies: A Cross Performance Assessment
Analyzing costs and greenhouse gas (GHG) emissions could be of great importance for the water utilities to supply water services in a healthy and sustainable manner. In this study, we measured the eco-efficiency of several water utilities in England and Wales by incorporating GHG as an undesirable output. For the first time, we evaluated the eco-efficiency of the water production process using robust cross-efficiency data envelopment analysis (DEA) techniques. The further use of clustering and regression techniques allowed us to better understand the drivers of eco-efficiency. The results showed that the mean eco-efficiency of the water sector was 0.748, which indicates that costs and GHG e…
Assessing the dynamic eco-efficiency of Italian municipalities by accounting for the ownership of the entrusted waste utilities
Abstract This study evaluates and compares the dynamic eco-efficiency of municipalities with publicly owned, privately owned, and mixed ownership solid waste utilities by estimating the Meta-frontier Malmquist-Luenberger productivity index for a sample of 68 major Italian towns. On average, the eco-productivity of Italian waste service providers increased by 8% from 2016 to 2019. Although municipalities with private utilities improved their eco-productivity most, the differences among the three clusters reflecting utility ownership are not statistically significant. The results show that publicly owned waste operators drive technology and that the technological levels of private utilities h…
Assessing productivity changes in water companies: a comparison of the Luenberger and Luenberger-Hicks-Moorsteen productivity indicators
Interest in evaluating productivity changes in water companies has increased in recent years. In this paper, for the first time, we employ the Luenberger-Hicks-Moorsteen Productivity Indicator (LHMPI) to evaluate productivity changes in a sample of Chilean water companies from 2010 to 2016. Productivity change estimations obtained by both the Luenberger Productivity Indicator (LPI) and the LHMPI are compared. Moreover, both indicators were computed assuming constant and variable returns to scale technologies. The LHMPI estimates illustrate that productivity in Chilean water companies has slightly improved over the period studied due to the positive trend of outputs, whereas the inputs negat…
Estimating the environmental and resource costs of leakage in water distribution systems: A shadow price approach.
Water scarcity is one of the main problems faced by many regions in the XXIst century. In this context, the need to reduce leakages from water distribution systems has gained almost universal acceptance. The concept of sustainable economic level of leakage (SELL) has been proposed to internalize the environmental and resource costs within economic level of leakage calculations. However, because these costs are not set by the market, they have not often been calculated. In this paper, the directional-distance function was used to estimate the shadow price of leakages as a proxy of their environmental and resource costs. This is a pioneering approach to the economic valuation of leakage exter…
Performance assessment of water companies: A metafrontier approach accounting for quality of service and group heterogeneities
Abstract The assessment of water companies’ efficiency, productivity and quality of service is part of the process to set water tariffs and therefore, is relevant for regulators and customers. However, the water industry involves several heterogeneous water companies. Following a pioneering approach, this study estimates productivity change and its drivers considering the non-homogeneous nature of the water companies and incorporating quality of service variables as undesirable outputs. In doing so, the metafrontier Malmquist Luenberger productivity index was estimated for a sample of English and Welsh water and sewerage companies (WaSCs) and water only companies (WoCs) over the years 2001–…
Drivers of productivity change: a comparison of English and Welsh water only and water and sewerage companies
In regulated industries, such as the water industry, it is of great significance to estimate productivity change as it helps policy makers to evaluate the effectiveness of regulatory regime and ind...
Accounting for service quality to customers in the efficiency of water companies: evidence from England and Wales
This paper investigates the role of service quality to customers in the efficiency assessment of water companies in England and Wales. To achieve this, data envelopment analysis techniques are employed to compute the technical efficiency of the water companies following two approaches: (i) traditional assessment based on quantity variables (without the inclusion of service quality variables) and (ii) alternative assessment considering quantity and service quality variables as undesirable outputs. The analysis covers 22 water and sewerage companies and water only companies providing drinking water services. The results indicate that the traditional efficiency assessment reveals a high level …
Evaluating the Eco-Efficiency of Wastewater Treatment Plants: Comparison of Optimistic and Pessimistic Approaches
The assessment of wastewater treatment plant (WWTP) performance has gained the interest of water utilities and water regulators. Eco-efficiency has been identified as a powerful indicator, as it integrates economic and environmental variables into a single index. Most previous studies have employed traditional data envelopment analysis (DEA) for the evaluation of WWTP eco-efficiency. However, DEA allows the selection of input and output weights for individual WWTPs for the calculation of eco-efficiency scores. To overcome this limitation, we employed the double-frontier and common set of weights methods to evaluate the eco-efficiency of a sample of 30 WWTPs in Spain. The WWTPs were ranked b…
Assessing the marginal cost of reducing greenhouse gas emissions in the English and Welsh water and sewerage industry: A parametric approach
Abstract Reducing greenhouse gas (GHG) emissions involves effort from different sectors of the economy, including the water and sewerage industry. This study estimates the marginal cost of curtailing GHG emissions in the water and sewerage industry using stochastic frontier analysis techniques for a sample of ten English and Welsh water and sewerage companies over the 2010–2019 period. Results illustrated that the average marginal cost of reducing GHG emissions was 0.181 £/Kg CO2 equivalent. The marginal cost estimated notably differs across companies and over time. Findings further illustrate the impact of water companies' operating characteristics on the marginal cost of reducing carbon e…
Measuring the wastewater treatment plants productivity change: Comparison of the Luenberger and Luenberger-Hicks-Moorsteen Productivity Indicators
Abstract It is essential to assess the productivity of wastewater treatment plants (WWTPs) to improve their economic and technical performance over time. In doing so, reliable indexes should be used to avoid biased conclusions leading to unsuccessful policy and managerial measures. Ratio-based indexes are typically employed, but are infeasible when any of the variables are equal or close to zero. To overcome this limitation, this paper presents the innovative approach of applying and comparing two difference-based productivity indicators, Luenberger (LPI) and Luenberger-Hicks-Moorsteen (LHMPI), to evaluate how productivity changes in a sample of WWTPs. Because the LHMPI is an additively com…
Estimating performance and savings of water leakages and unplanned water supply interruptions in drinking water providers
Producción Científica