Reprint of: Dynamic efficiency in the English and Welsh water and sewerage industry

• Data Envelopment Analysis is used to model dynamic efficiency in the water industry.
• The water utility industry in England and Wales is regionally separated.
• Environmental variables capture differences in the operating environment in the regions.
• A capital expenditure bias exists based on the dynamics of investment.

The English and Welsh water and sewerage industry is characterised by indivisible capital which has a long service life. Previous studies of efficiency for the English and Welsh water and sewerage industry take a static framework, assuming all inputs can be adjusted instantaneously. This paper measures dynamic efficiency by incorporating intertemporal links of capital within the production function for the English and Welsh water and sewerage industry for the period 1997–2011. Dynamic Data Envelopment Analysis (DEA) considers capital as a quasi-fixed input and is modelled as a contemporaneous output into current production and an input from past production. The results show that the inadequate intertemporal allocation of quasi-fixed inputs is the largest contributor of inefficiency.