Portrait of Alan Horncastle

Alan Horncastle : Partner

Alan has 30 years of professional experience in applying economics to aid decision-making, in particular in the regulated sectors. He specialises in efficiency measurement and assessments, regulatory reform and regulatory incentive design.

He has provided strategic advice and expert evidence on mergers and acquisitions, regulatory due diligence, business planning, regulatory determinations, appeals and court cases. He has advised companies, investors, governments and regulatory authorities in the water, energy, transport, financial services and communications sectors across Europe.

Alan is co-author of A Practitioner’s Guide to Stochastic Frontier Analysis using Stata with S. Kumbhakar and H.-J. Wang, published by Cambridge University Press in 2015. The book provides practitioners in academia and industry with a step-by-step guide on how to conduct efficiency analysis using the econometric approach, stochastic frontier analysis.

Alan speaks English.

Tel: +44 (0) 1865 253015

Alan's specialisms include:

professional experience

  • Advice on efficiency issues for RIIO-ED2 controls (2020–21)

  • Efficiency advice to Royal Mail, including internal benchmarking (1999–2014, 2020–21)

  • Advice on productivity and efficiency for RIIO-T2 controls (2018–21)

  • Advice on regulatory issues, productivity and efficiency for RIIO-GD2 controls (2017–21)

  • Advice to water companies on regulatory and efficiency issues during PR19 and during the CMA inquiry into their appeal of the PR19 Final Determinations (2016–21)

  • Advice on benchmarking and efficiency monitoring for Highways England (2014–21)


  • Horncastle, A., Duffy, J., Xen Ng, C. and Krupa, P. (forthcoming), ‘Benchmarking in the European water sector: applications of production economics’ in Ray S.C., Chambers R., Kumbhakar S. (eds) Handbook of Production Economics, Volume II, Springer.

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

  • Horncastle, A., Colarullo, G. and Aitken, J. (2012), ‘The Case of South Staffordshire/Cambridge: Is Clearer Water Emerging?’, Competition Law Journal, 11:4, pp. 334–41.

  • 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.


  • MSc Econometrics and Mathematical Economics, London School of Economics, UK

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

Latest Insights:  Alan Horncastle

16 minute read
On 7 July, Ofwat published its draft methodology for its next price review (PR24), setting out in detail how it plans to assess expenditure, financing costs, performance targets and incentives…
8 minute read
In December 2020, Ofgem published its Sector Specific Methodology Decision (SSMD) for the RIIO-ED2 price control covering the electricity distribution (ED) sector. In this article, we review Ofgem’s RIIO-ED2 SSMD…
13 minute read
On 17 March, the Competition and Markets Authority (CMA) published its summary of Final Determinations (FDs) of Ofwat’s PR19 price review for four disputing companies (Anglian Water, Bristol Water, Northumbrian…
11 minute read
Having published its Draft Determinations (DDs) in July 2020,1 on 8 December 2020, Ofgem published its Final Determinations (FDs) for the RIIO-2 price controls for the GB electricity transmission (ET),…

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