Alan Horncastle


+44 (0) 1865 253019

Location: Oxford

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Alan leads Oxera’s work on performance assessment and the water sector. He has provided strategic and detailed efficiency and cost-modelling advice for business planning purposes, on transactions, and during numerous price control reviews and Competition Commission cases. His advice has been provided at the executive board and senior management level, including expert oral advice at formal meetings with regulators, and hearings during Competition and Markets Authority (CMA) inquiries. He has provided advice for companies and regulators in the energy, transport, water, financial services and communications sectors across Europe. Alan is co-author of A Practitioners Guide to Stochastic Frontier Analysis using Stata with S. Kumbhakar and H.-J. Wang, published by Cambridge University Press in 2015.

Selected project experience

  • Advised South West Water during the CMA inquiry into its merger with Bournemouth Water (2015)

  • Advice to the water industry on efficiency issues during PR14, including advice to Bristol Water during the CMA inquiry into its appeal of the PR14 Final Determinations (2013–15)

  • Advice on efficiency issues for the Energy Networks Association and electricity DNOs for RIIO-ED1, including expert evidence as part of the CMA inquiry following British Gas Trading’s appeal of the RIIO-ED1 price control (2011–15)

  • A review of the efficiency regime for a German gas transmission company (2013)

  • Advice to a group of Italian water companies on developing a framework to assess cost efficiency (2013–14)

  • Advice to BT on efficiency and incentives (2011–13)

  • Advice on efficiency for an energy transmission company for RIIO-T1 (2011–13)

  • Efficiency advice to Royal Mail, including internal benchmarking (1999–2014)

  • Efficiency advice to the Finnish energy industry (2012)

  • Developed a cost forecasting framework, including an international benchmarking study, for a top-ten international airport (2011–12)

  • Advised South Staffs Water on the impact of the merger with Cambridge Water on the comparative regime for the Competition Commission inquiry (2011–12)

  • Advice on efficiency issues for a Belgian energy distribution network (2011–12)

  • Strategic and regulatory efficiency advice to Network Rail in the context of ongoing sector reform and in preparation for the forthcoming price control (2011–12)

  • Advice on the efficiency regime for district heating in Europe (2011–12)

  • Advice to a UK gas distribution company on its Business Plan submission for the RIIO-GD1 regulatory review (2011–12)

  • Advice to a European Energy Regulator on alternative performance assessment approaches in electricity and gas networks (2010–12)

  • Advice on regulatory reform, including the efficiency regime, in Estonia (2010–12)

  • Advice on competition and regulatory reforms in the water industry (2010–11)

  • Examined consumption efficiency in the retail investment products market (2010)

  • Advice to major GB bus operators reviewing the likely impact of a change in the concessionary fares regime, including the efficient incremental costs (2010)

  • Efficiency advice for ESB for PR3 and PR4 (2009–14)

  • Review of the GB rail industry’s demand forecasting framework (2008–10)

  • Strategic and efficiency advice in the bus, train and aviation sectors (2008–10)

  • Strategic, regulatory and efficiency advice for Thames Water for PR09 (2008–10)

  • Advised the boards, and legal and financial advisers, of water and energy companies on potential mergers and acquisitions (2001–13)

  • Input price inflation and indexation advice for LUL (2008)

  • Advised Ofwat on the implementation of new approaches to assessing expenditure, including the menu approach (2008)

  • Benchmarking of indirect and central Infraco costs for OPPPA (2007–08)

  • Assessments of Network Rail’s efficiencies for ORR, and ‘Recommendations on how to model efficiency for future price reviews’ (2003–09)

  • Advice to a bidder for the Midlands train operating franchise (2006–07)

  • Advised the BBC on the potential for efficiency improvements (2005–06)

  • Led Oxera’s efficiency advice for a number of price control reviews in energy, water, transport and communications (1996–2013)

  • Led Oxera’s efficiency advice for the Competition Commission inquiries of Manchester Airport (1997), British Gas Transco (1997), Mid Kent Water (2000), BAA (2002), a UK mobile phone operator (2002), Vivendi Water UK–Southern Water (2002), Mid Kent Water–South East Water (2007), Bristol Water (2010), and local bus services (2010) (1997–2010)

Selected publications

  • Kumbhakar, S., Wang, H.-J. and Horncastle, A. (2015), A Practitioners Guide to Stochastic Frontier Analysis using Stata, Cambridge University Press.

  • Arias, L. and Horncastle, A. (2011), ‘Lessons from mergers and Alliances in the British Water Industry’, chapter 3, in A. Estache (ed.), Emerging Issues in Competition, Collusion and Regulation of Network Industries, Centre for Economic Policy Research.

  • Silva Portela, M.C., Thanassoulis, E., Horncastle, A. and Maugg, T. (2011), ‘Productivity change in the Water Industry in England and Wales: Application of the Meta-Malmquist Index’, Journal of the Operational Research Society, 62, pp. 2173–88.

  • Kumbhakar, S. and Horncastle, A. (2010), ‘Improving the Econometric Precision of Regulatory Models’, Journal of Regulatory Economics 38:2, October, pp. 144–66.

  • Meaney, A., Horncastle, A. and Mahmood, A. (2010), ‘Efficiency, (Over-) Compensation and State Aid for PSOs’, Competition Law Journal, 9:3, pp. 371–8.

  • Kumbhakar, S. and Wang, H.-J., with Horncastle, A. (2010), ‘Estimation of Technical Inefficiency in Production Frontier Models Using Cross-Sectional Data’, Indian Economic Review, 45:2, pp. 7–77.

  • Fields, L., Horncastle, A. and Noble, R. (2009), ‘Water competition and the Cave Review: a clear way forward?’, Competition Law Journal, 8:3, pp. 238–47.

  • Horncastle, A., Jevons, D., Dudley, P. and Thanassoulis, E. (2006), ‘Efficiency Analysis of Delivery Offices in the Postal Sector Using Stochastic Frontier and Data Envelopment Analyses’, chapter 10, pp. 149–64, in A. Crew and P.R. Kleindorfer (eds), Liberalization of the Postal and Delivery Sector, Edward Elgar.


  • MSc Econometrics and Mathematical Economics, London School of Economics

  • BSc Economics, Analytical and Descriptive, London School of Economics

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