Estimation and evaluation of productivity change and its drivers in the English and Welsh water sector: a stochastic cost frontier approach

ABSTRACT

Estimating productivity change and its determinants is of great importance when measuring the performance of a firm. A true random effect cost model was employed to measure the cost efficiency of water companies in England and Wales from 1993 to 2016. Subsequently, total factor productivity change was estimated and decomposed into cost-efficiency change, technical change, scale efficiency change, output effect and residual price effect. The results indicate that the English and Welsh water industry increased its productivity over the period examined at a rate of about 2.1%, and it was influenced primarily by technical change. The price reviews appear to have a positive impact on the productivity of water-only companies during the whole period examined. In the case of water and sewerage companies, the 1994 and 1999 price reviews had a positive impact on productivity, whereas the last two price reviews had an adverse impact.     

Cost Efficiency of English and Welsh Water Companies: a Meta-Stochastic Frontier Analysis

Water Resources Management - In regulated industries it is important to identify appropriate performance benchmarks to incentivize companies’ performance. This study applies a stochastic...     

The welfare costs of non-marginal water pricing: evidence from the water only companies in England and Wales

The evaluation of the economic efficiency of regulatory schemes is essential for regulators and utilities. In this study it is analysed for the first time the welfare costs of non-marginal cost pricing in the water supply in England and Wales, by computing the deadweight loss of the water only companies (WoCs) that existed over the period of 1993–2009. The results indicate that the current price schemes can have substantial efficiency costs. Our estimates show that the loss of efficiency for the WoCs lies between 15 and 60 million GBP over the period 1993–2009. These amounts could have been redistributed either to the companies in terms of profits or to the consumers via price reductions. The methodology and results of this study are of great interest for both regulators and water utilities managers to evaluate the effectiveness of price regulation and make informed decisions.     

Assessment of the Total Factor Productivity Change in the English and Welsh Water Industry: a Färe-Primont Productivity Index Approach

The assessment of productivity change across companies and over time is of great importance for water utilities managers and regulators. In this paper, for the first time, we apply the Färe-Primont productivity index (FPI) to evaluate the productivity change for the 10 water and sewerage companies (WaSCs) and 12 water only companies (WoCs) in England and Wales during the years 2001–2008. The FPI is the only index that without price data allows making comparisons involving many firms and many periods. The results indicate that during the years 2001–2004 productivity improved which was mainly attributed to gains in efficiency whereas technical change remained constant, the exception being the year 2004. During the years 2005–2008 productivity showed a declining trend and any gains in efficiency were lost to the highly negative technical change on productivity growth. From a policy perspective, it has been illustrated the importance of using a reliable index to compute the productivity change of water companies when the performance of companies is used to set water tariffs. Finally, the decomposition of productivity change into several drivers allows water utilities and managers to identify the main factors on which they should act to improve productivity of the company.     

The Role of Interleukins in Recurrent Implantation Failure: A Comprehensive Review of the Literature

Recurrent implantation failure (RIF) is a multifactorial condition affecting 10–15% of in vitro fertilization (IVF) couples. Data suggest that functional dysregulation of the endometrial immune system constitutes one of the main pathophysiological mechanisms leading to RIF. The aim of this article is to provide a thorough presentation and evaluation of the role of interleukins (ILs) in the pathogenesis of RIF. A comprehensive literature screening was performed summarizing current evidence. During implantation, several classes of ILs are secreted by epithelial and stromal endometrial cells, including IL-6, IL-10, IL-12, IL-15, IL-18, and the leukemia inhibitory factor. These ILs create a perplexing network that orchestrates both proliferation and maturation of uterine natural killer cells, controls the function of regulatory T and B cells inhibiting the secretion of antifetal antibodies, and supports trophoblast invasion and decidua formation. The existing data indicate associations between ILs and RIF. The extensive analysis performed herein concludes that the dysregulation of the ILs network indeed jeopardizes implantation leading to RIF. This review further proposes a mapping of future research on how to move forward from mere associations to robust molecular data that will allow an accurate profiling of ILs in turn enabling evidence-based consultancy and decision making when addressing RIF patients.     

Decomposition of Cost Efficiency Into Persistent and Transient Efficiency in the Provision of Water Services: Evidence from England and Wales

Water Resources Management - Performance assessments of water utilities are essential to protect the interests of citizens, because utilities operate under natural monopolies and their costs are...     

Molecular Drivers of Developmental Arrest in the Human Preimplantation Embryo: A Systematic Review and Critical Analysis Leading to Mapping Future Research

Developmental arrest of the preimplantation embryo is a multifactorial condition, characterized by lack of cellular division for at least 24 hours, hindering the in vitro fertilization cycle outcome. This systematic review aims to present the molecular drivers of developmental arrest, focusing on embryonic and parental factors. A systematic search in PubMed/Medline, Embase and Cochrane-Central-Database was performed in January 2021. A total of 76 studies were included. The identified embryonic factors associated with arrest included gene variations, mitochondrial DNA copy number, methylation patterns, chromosomal abnormalities, metabolic profile and morphological features. Parental factors included, gene variation, protein expression levels and infertility etiology. A valuable conclusion emerging through critical analysis indicated that genetic origins of developmental arrest analyzed from the perspective of parental infertility etiology and the embryo itself, share common ground. This is a unique and long-overdue contribution to literature that for the first time presents an all-inclusive methodological report on the molecular drivers leading to preimplantation embryos’ arrested development. The variety and heterogeneity of developmental arrest drivers, along with their inevitable intertwining relationships does not allow for prioritization on the factors playing a more definitive role in arrested development. This systematic review provides the basis for further research in the field.     

Assesing the Impact of Quality of Service on the Productivity of Water Industry: a Malmquist-Luenberger Approach for England and Wales

Assessing productivity change over time and identifying its determinants is a valuable tool for water regulators when setting water tariffs. However, in a price cap regulatory framework such as in England and Wales policy makers should give attention to quality of service issues. Previous studies that assessed the productivity change of the English and Welsh water industry did not include the lack of quality of service to customers as undesirable outputs. To overcome this limitation, and as a pioneering approach, we estimated the Malmquist-Luenberger Productivity Indicator and its components, efficiency and technical change, for the 10 water and sewerage companies and the 12 water only companies over the period 2001–2008. To explore the role of quality of service to customers on the productivity change over time, we contrasted our results with a conventional measure of productivity change namely the Luenberger productivity indicator. The findings suggest that from 2001 to 2004 water companies made significant efforts to improve the quality of the service provided to customers, whereas after 2005 companies’ performance regarding customer services was considered as poor. Results excluding quality of service variables illustrated that productivity declined during all years evaluated. However, when the quality of service was introduced in the assessment, productivity improved by 4.13 % from 2000 to 2004 whereas it declined by 16.96 % in the following years. From a policy perspective, water utility regulators need to pay attention to quality of service issues when assessing companies’ performance and setting water tariffs under comparative yardstick regimes.