Profit change and its drivers in the English and Welsh water industry: is output quality important?

Abstract The assessment of profit change over time and its drivers is essential to analyse firms' financial performance. This paper investigates profit change and its components for the 10 English and Welsh water and sewerage water companies over the period 1991–2008 and for three regulatory sub-periods. Profit changes and their drivers are computed following two approaches, namely: without controlling for water and sewerage quality issues, and after decomposing the output effect into high quality and low quality output effect. In both cases, profit change is decomposed into various factors such as quantity and price effect, technical change, efficiency change, resource mix, product mix, an…