We examine every case to identify the most effective expert witnesses.

We examine every case to identify the most effective expert witnesses.

Gregor Langus

Vice President*

Gregor Langus leads Cornerstone Research’s Brussels competition team. Dr. Langus is a leading European competition economist who supports clients and provides expert testimony in antitrust investigations, merger reviews, competition damages matters, and arbitration proceedings. He has extensive experience in innovation, digital markets, and intellectual property matters, with a focus on information technology markets, online platforms, standard essential patents (SEPs), and copyright issues.

Dr. Langus has worked on matters in multiple jurisdictions, including before the European Commission (EC), the U.S. Department of Justice (DOJ), the Federal Trade Commission (FTC), and competition authorities and courts of several European Union member states.

Dr. Langus served in the Chief Economist’s Team in the EC’s Directorate-General for Competition (DG COMP) for over seven years, in two separate appointments. During that time, he worked on numerous complex merger reviews, including IBM/RedHat, Dow/Dupont, Blackstone/Celanese, Broadcom/Brocade, Microsoft/LinkedIn, ASL/Arianespace, Wabtec/Faiveley, Siemens/DresserRand, Intel/McAfee, Oracle/Sun, EDF/British Energy, Campina/Friesland, and TomTom/TeleAtlas. Dr. Langus also consulted on matters alleging abuse of market power and information exchange.

Dr. Langus is the lead author of several competition policy studies focused on copyright, licensing, merger control, and telecommunications issues. His academic articles have been published in peer-reviewed journals, including the International Journal of Industrial Organization, Economics Letters, the Journal of Competition Law and Economics, and Concurrences.

Dr. Langus has extensive consulting experience as head of CompetitionSphere, and in senior roles with major economics consulting firms. Dr. Langus also has teaching experience as a lecturer at Tilburg University.

Dr. Langus speaks widely on competition, mergers, and SEP issues. Who’s Who Legal has recognized him as a Thought Leader among top global competition economists.


We examine every case to identify the most effective expert witnesses.

Andrew Sweeting

Professor, Department of Economics,
University of Maryland, College Park;
Former Director, Bureau of Economics,
U.S. Federal Trade Commission

Andrew Sweeting is a former director of the U.S. Federal Trade Commission’s (FTC’s) Bureau of Economics. An industrial organization economist, Professor Sweeting specializes in competition and antitrust, including merger analysis, applied econometrics, and structural modeling.

While at the FTC, Professor Sweeting oversaw many merger investigations conducted by the Agency, and was director when the 2020 Vertical Merger Guidelines were released. He was also involved in high-profile consumer protection investigations, including several related to digital platforms and data security. In addition to his tenure at the FTC, Professor Sweeting has served as an academic visitor at the U.S. Department of Justice’s Economic Analysis Group, and as an expert on the Academic Panel of the U.K. Competition Commission (now the U.K. Competition and Markets Authority).

Global Competition Review recognized Professor Sweeting to its inaugural list of the world’s most important antitrust academics. His wide-ranging research has analyzed the impact of mergers on prices, product variety, and product repositioning. He has also addressed collusion in wholesale electricity markets, the performance of different auction designs, dynamic pricing in online resale markets, and the effects of alternative copyright policies in the radio industry. In addition, he has researched the effect of government bailouts, how targeted advertising affects market structure and competition, and firms’ strategic use of pricing and capacity choices to influence future competition.

Professor Sweeting has conducted empirical research in a range of industries, including radio, television, advertising, consumer packaged goods, energy markets, online resale markets, transportation, and government procurement and timber auctions.

A widely published author, Professor Sweeting’s work has appeared in leading economics journals, such as Econometrica, the American Economic Review, the Journal of Political Economy, and the RAND Journal of Economics. He has been awarded several multiyear research grants from the National Science Foundation. In 2018, he received the Robert F. Lanzillotti Prize for the best paper in antitrust economics for a coauthored article on post-merger repositioning in the airline industry.

Professor Sweeting is a former editor of the Journal of Industrial Economics and a former foreign editor of the Review of Economic Studies. He is a research associate of the National Bureau of Economic Research (NBER) and a research fellow of the Centre for Economic Policy Research (CEPR).

In his more than two decades as an educator, Professor Sweeting has been honored numerous times for excellence in teaching. Before joining the faculty of the University of Maryland, he held positions at Duke University, Northwestern University, and St. Catherine’s College, Oxford.

We examine every case to identify the most effective expert witnesses.

Margaret K. Kyle

Chair in Intellectual Property and Markets for Technology,
MINES ParisTech

Margaret Kyle is a noted authority on competition, intellectual property (IP), and innovation, with extensive multinational experience with life sciences and healthcare topics.

Professor Kyle has been retained as an expert witness in multiple matters and has significant testifying experience, including at trial. She has provided testimony on a range of issues, including damages related to alleged product misrepresentation, pricing of pharmaceutical products, and nascent competition. The global Women@Competition platform named Professor Kyle among forty notable women competition professionals in their forties. Global Competition Review recognized her to its inaugural list of the world’s most important antitrust academics.

In her academic work, Professor Kyle has examined the impact of antitrust, trade, and IP policies on R&D investment, innovation, and competition. In particular, Professor Kyle has substantive experience with issues related to pricing of pharmaceutical products, R&D productivity, new product distribution, and competition between branded and generic pharmaceutical products. In addition, she has written about antitrust merger enforcement issues in pharmaceutical markets, with applications to other dynamic markets characterized by innovation. In the context of COVID-19, she has analyzed how incentives can promote the development of new medical technologies and advance the rapid manufacture of tests and treatments.

Professor Kyle’s previous positions include visiting professor of strategy at Northwestern University’s Kellogg School of Management; visiting scholar at the Center for the Study of Income and Productivity at the U.S. Federal Reserve Bank of San Francisco; professor at the Toulouse School of Economics; assistant professor at the London Business School, Duke University, and Carnegie Mellon University; and visiting professor at the University of Hong Kong.

Professor Kyle consults to policy entities in the United States, Europe, and the UK on competition, economics, and innovation topics. She is a member of DG Competition’s Economic Advisory Group on Competition Policy. At France’s Conseil National de Productivité, which advises the French Prime Minister and the Minister of Economic Affairs, she is one of eleven independent academic economists analyzing the country’s productivity and competitiveness, particularly issues linked to the Euro Zone. She coauthored a note on policies to encourage pharmaceutical innovation for France’s Conseil d’Analyse Économique. In the UK, Professor Kyle serves on the Research Committee for the Office of Health Economics.

Professor Kyle has coauthored chapters in the Handbook of Health Economics, the Oxford Handbook of the Economics of the Biopharmaceutical Industry, and Elsevier’s Encyclopedia of Health Economics. Her academic papers have been published in leading economics, strategy, and health policy journals. In 2024, Professor Kyle won a Concurrences Antitrust Writing Award for her coauthored article, “The Economics of New Product Launches and Access to Pharmaceutical Products in the EU.”

Professor Kyle is associate editor of the International Journal of Industrial Organization. She has been invited to speak at numerous conferences on issues such as nascent competition, reverse payment patent settlements, and excessive pricing.

We examine every case to identify the most effective expert witnesses.

Liam Colley

Senior Vice President

Liam Colley heads Cornerstone Research’s European competition practice. Mr. Colley is a testifying economics expert specializing in competition, antitrust damages, and economic regulation issues. He has more than twenty-five years of experience as a consultant and testifying expert. His experience includes multiple high-profile matters before U.K. and European Union courts and competition regulators. Citing the “unassailable quality of his work,” Who’s Who Legal has named Mr. Colley a leading competition economist, as well as a Thought Leader and Global Leader in the competition field.

Antitrust and competition

Mr. Colley has consulted on a range of competition matters before the European Commission, national competition authorities, regulators, and courts. His expertise includes matters arising in automotive; financial services; insurance; technology, media, and telecom (TMT); and transportation. He has supported clients on numerous antitrust investigations and market inquiries. In addition, Mr. Colley has worked on multiple mergers, particularly on matters involving efficiencies and failing firm defenses.

Antitrust damages

Mr. Colley has wide experience estimating damages that arise from breaches of competition rules. In cartel damages matters, he has prepared numerous expert reports in the context of high court litigation, arbitration, mediation, and settlement negotiations. He has addressed class action issues and worked on many stand-alone and follow-on actions in abuse of dominance cases.

Mr. Colley has served as a testifying expert before the U.K. High Court and the U.K. Competition Appeal Tribunal (CAT) on both antitrust damages matters and regulatory appeals.

Mr. Colley publishes and speaks widely on competition and damages issues. Before joining Cornerstone Research, for many years he led the global economics practice of a major professional consulting firm.

Competition Capabilities

Expert Assessments of Complex Economic Issues

‘Horizontal’ co-operation agreements are between competitors at the same level of the supply chain. In these matters, we assess the economic incentives of the alleged participants, and test hypotheses that distinguish competitive from collusive behaviour. We assist on cases involving:

  • Research and development agreements
  • Production agreements, including subcontracting and specialisation
  • Purchasing agreements
  • Commercialisation agreements
  • Standardisation agreements
  • Information exchange

‘Vertical’ co-operation agreements are between market participants at different levels of the supply chain. The European Commission’s Vertical Restraints guidelines accept that competition concerns can only arise from vertical agreements if there is insufficient competition at one or more levels of the supply chain, i.e. at the supplier and/or buyer levels. Moreover, vertical restraints are generally less harmful than horizontal restraints and may provide substantial scope for efficiencies.

We assist on cases involving:

  • Single branding agreements
  • Exclusive dealing agreements
  • Exclusive customer allocations
  • Selective distribution agreements
  • Franchising
  • Category management agreements
  • Tying agreements
  • Resale price restrictions
  • Most Favoured Nation (MFN) restrictions
  • Non-compete type restraints

We help clients navigate all stages of merger investigations, whether they are in front of national competition authorities, the European Commission or are subject to regulatory scrutiny on both sides of the Atlantic and elsewhere.

Our experts’ deep knowledge of our clients’ markets supports relevant and robust economic and econometric evidence for investigations. Counsel also benefit from our deep expertise of competition economics, accounting, data science and survey methods.


Abuse of dominance cases may involve allegations of exclusionary or exploitative conduct by a dominant firm against rivals in the marketplace. Such exclusionary conduct may lead to harm to consumers through increased prices, less innovation and reduced quality.


Private actions for damages can be stand-alone allegations of anti-competitive conduct or agreements pursued through the courts. Alternatively, they may ‘follow-on’ from a competition agency’s decision that a firm’s conduct amounted to an abuse of dominance or formed part of an illegal anti-competitive agreement.

Cornerstone Research experts have deep expertise in assessing both the substance of allegations in stand-alone cases and also, in particular, the quantum of competition damages in follow-on cases.

  • Damages from cartels or other anti-competitive horizontal agreements
  • Damages from anti-competitive vertical agreements
  • Damages from exclusionary or exploitative abuse by a dominant firm

Our experts have deep experience of market investigations (sector inquiries). Specifically, we have worked to support clients in such cases in a number of jurisdictions including in front of the CMA in the UK and the South African Competition Commission.

In such cases, we work as expert economic and financial advisers for parties subject to a market investigation. Doing so can entail a variety of roles including supporting external legal advisers providing economic advice to corporate boards, supporting in-house project teams managing the firm’s contributions to an inquiry, and developing expert economic submissions to help inform the competition agency’s evaluation.

Our role may encompass:

  • Developing in-house perspectives of both likely and desirable outcomes from an inquiry
  • Responding to competition agency working papers and provisional findings
  • Helping to prepare senior management before their participation in agency hearings
  • Developing economic and financial submissions drawing on a client’s own data
  • Developing economic and financial submissions based on market-wide data when this is made available to economic advisers via disclosure rooms or confidentiality rings
  • Easing the burden on management involved in responding to a large volume of substantial agency questions about the detail of a client’s businesses. For example, on past cases we have provided management with draft questionnaires well in advance of the CMA issuing its own market and financial questionnaires.
  • Advising on likely agency interpretations of the available documentary evidence and data.

EU Member states sometimes subsidise undertakings on a selective basis. Such subsidies could take many forms including tax relief, guarantees, or providing goods and services on preferential terms.

State aid measures are those which affect trade between member states and, in particular, would distort competition by providing the recipient with advantages on a selective basis, for example to specific companies or industry sectors, or to companies located in specific regions.


Featured Cases and Publications

26 June 2024

United Kingdom: Recent judgments shed light on importance of economic evidence

The authors reflect on key takeaways from three important judgments in UK competition litigation.

4 June 2024

Balanced and Transparent Antitrust in the AI Space

The authors examine the role of European Union (EU) competition policy and adjacent EU regulations in the emerging artificial intelligence space.

4 June 2024

Procompetitive Effects of Mergers in the 2023 Merger Guidelines: What Counts and Where?

The authors provide an overview of the Agencies’ guidance for assessing procompetitive effects in merger evaluation, with a focus on changes in in ...

10 April 2024

Cornerstone Research Staff and Affiliated Expert Win 2024 Antitrust Writing Awards

Concurrences Review recognized winners in the intellectual property and mergers categories, selected from leading antitrust and competition article...

20 February 2024

Brussels Team Expands with Experienced Competition Hire

Dr. Norbert Maier joins Cornerstone Research, with deep antitrust law and competition expertise from the EU Commission DG COMP team.

5 February 2024

Cornerstone Research Named Among 2024 Outstanding Global Economic Consultancies

Global Competition Review describes the firm as “ideally placed to tackle the most complex and demanding competition mandates.”

12 January 2024

2024 Antitrust Writing Awards

Cornerstone Research staff and affiliated experts are nominated in Concurrences Review’s annual selection of leading articles.

4 December 2023

Innovation in Merger Control

This article discusses the considerations for forward looking economic analysis of dynamic innovation and R&D effects in mergers.

6 November 2023

Bid Rigging and Umbrella Damages

This article analyzes the role of umbrella damages when conducting damage assessment in bid-rigging cases.

18 October 2023

Dr. Joanna Tsai Joins Cornerstone Research as Vice President

Prominent merger economics expert brings global experience in high-stakes mergers, acquisitions, joint ventures, and other antitrust matters.

How can we help you?

For more information or assistance with a specific matter, please contact us.