Iestyn Williams

Iestyn is a Partner in RBB’s London office. He has provided competition economics advice to clients across a diverse set of issues and market settings for over 20 years. His practice has increasingly focused on providing expert economic evidence in litigation cases – for claimants and defendants, in respect of standalone and follow-on cases.

Iestyn has a PhD in Economics from the London School of Economics. Before embarking on his consulting career, he was an academic economist.

Iestyn has advised on a wide array of competition matters, involving pricing and non-pricing conduct as well as mergers and market investigations.

Iestyn regularly acts as an expert economist in litigation cases, and has prepared numerous opinions and reports for clients involved in proceedings before tribunals and courts, including the English High Court, the Scottish Court of Session, and the UK Competition Appeal Tribunal, as well as the Finnish Market Court and the Singapore Competition Appeal Board.

During the early part of his consulting career, Iestyn specialised in energy cases, and he continues to work on assignments for clients competing in liberalised industries and at the interface with natural monopoly.

Iestyn has written on a range of competition economics topics. He has also contributed to a number of studies for competition authorities, including as a lead author of reports on pass-through for the UK Office of Fair Trading and the European Commission. He has been a guest lecturer at Bristol University.

Before embarking on his consulting career, Iestyn was an academic economist specialising in the study of vertical and other contractual relationships. He has an undergraduate degree in economics from Cambridge University and an MSc in Econometrics and Mathematical Economics and a PhD from the London School of Economics.