Centre for Law, Economics and Society


Economic and Econometric Evidence in Competition Law: An Empirical Perspective

The increasing impact of economics (Industrial Organization – IO – , welfare economics, behavioral economics) on competition law is well documented.

The main tenets and principles of competition law have witnessed a profound transformation following the systematic recourse to economics as an external source of authority, the last few decades. More than in any other field of law, competition law is intrinsically linked with the discipline of economics, as this is shown by the frequent references to economic concepts and the methodology of competition and regulatory authorities, the case law of the courts and the expanding soft law relating to the interpretation of the competition law and regulatory statutes. 

A common feature of this transformation of the field of competition law is the emphasis put on a, mostly synchronic, analysis of the welfare effects of the specific commercial practice on consumers, users or more broadly economic efficiency (Lianos, 2007) . Indeed, an important part of the evidence presented in competition and regulatory law disputes is of economic nature, such as econometric techniques and economic models (Lianos & Genakos, 2012) .

Starting with merger control and moving slowly but steadily in the area of antitrust, economic evidence has become an essential ingredient of a successful competition law case, either at the level of authorities or courts, in competition law. The increasing importance of private enforcement for competition law violations in national courts raises also important questions of proof and evaluation of damages, thus bringing to the fore the interaction between economic evidence and the legal rules on the gathering and evaluation of evidence for adjudication.

As a consequence of the increasing relevance of economic evidence in competition law cases, the role of forensic expert economists is now pivotal in a competition law case. Evidence is often presented by experts employed by parties and providing advice on the economic merits of the case.

Legal professionals are thus working with economists in the preparation and assessment of a competition law case. The legal system has taken stock of the challenges presented by economic evidence and has regulated the way this evidence is assessed and its probative value examined. This is first achieved by the molding of the law of evidence so as to address the challenges of economic evidence (standard of proof).

Competition authorities have also developed soft law guidelines discussing "best practices" for the submission and assessment of economic and econometric evidence in administrative, as well as in judicial proceedings (e.g. Bundeskartellamt, Competition Commission, European Commission 2009 & 2011). However, these texts do not engage with the broader legal questions of evidence and how this should be assessed.

There is no comprehensive work in Europe (with the exception of Sibony 2008 , Lianos 2010 , Lianos & Genakos 2012), but also in the United States, addressing systematically the important issues raised by the transformation of the law of evidence, the extent of regulatory and judicial scrutiny of such evidence or legal concepts, such as causation, following the greater recourse to economics. 

Objectives and Project Plan

The case study will briefly describe the main aspects of the most commonly used types of economic evidence in competition law and regulatory analysis and will quantify their use in competition law decisions. The research will analyse the different forms economic evidence may take in competition law proceedings and will codify the different tools as these are listed in the economic literature with the aim to establish a taxonomy of economic evidence, according to a number of relevant factors (e.g. more or less formal - with regard to the use of advanced mathematical modelling) (Phase 1).

Based on the previous categorization of economic evidence, we will collect and codify information on all the publicly available decisions on merger, antitrust and cartel cases of the competition law authorities and court judgments in the selected jurisdictions with a significant content in competition law (from 2004 until 2012) (Phase 2).

We will be proceeding with the coding of all binding individual decisions of the competition authorities and judgments implementing competition law. The aim is to analyse both their frequency of use over time, but also to try to quantify the opinion of the authority or judge for the particular techniques used (hence the need for manual coding). This will be performed according to the following Opinion Score scale (Table 1). For an illustration, see Lianos & Genakos, 2012.

Table 1 - Opinion Score Scale
Opinion ScoreInterpretation
1The technique was discarded
2Strong objections were raised on aspects of the technique and the technique had no significant impact on conclusions
3The technique was taken into consideration as evidence, albeit with reservations
4The technique was taken seriously into consideration as evidence, however it was not solely relied upon to reach a conclusion
5The technique was very convincing and constituted a solid basis for a conclusion


We will then examine, with the support of content analysis software and manual coding, the interaction of these economic arguments in competition cases with other sorts of arguments, roughly classified as following: legal arguments (arguments linked to previous case law and/or interpretation of statutes and principally motivated by requirements of coherence in the legal reasoning), factual arguments (arguments relating to the factual evidence collected in this case and the inferences that can be made from that factual evidence with the help of practical reasoning), administrative/institutional design arguments (arguments relating to the nature of legal procedures, the limits of the competences or powers of the authority, concerns of effective administration of justice). The aim is to explore the relative weight of economic evidence in the decision-making process (Phase 3).

This information will be compared to the institutional characteristics of the legal process. How is the decision-making process organized in competition authorities? Are economists and lawyers working in integrated units or are they complete their analysis separately? What is the part of legal and economic analysis in the published decisions of these authorities?

What is the degree of judicial scrutiny of this economic evidence exercised by the courts and the corresponding deference to the analysis of the competition authorities? How courts are organized? Are there any specialized courts dealing with competition cases? Does this make any difference? What is the composition of these courts? What are the available instruments in the civil procedure rules of each jurisdiction for hearing expert economic evidence and assessing it (Phase 4)?

Current Phase of Implementation

The project is currently in Phase 1.

The project is supported by the UNCTAD Research Platform Initiative: http://unctad.org/en/Pages/DITC/CompetitionLaw/ResearchPartnership/Economic-Competition.aspx

Footnote 1: Lianos (2007), La Transformation du droit de la concurrence par le recours á analyse économique (Bruylant, 2007).

Footnote 2: Lianos/C. Genakos (2012), Econometric Evidence in EU Competition law: An Empirical and Theoretical Analysis, CLES Research paper 06/12, 1-119 pp.

Footnote 3: A.-L. Sibony (2008), Le Juge et le raisonnement économique en droit de la concurrence (LGDJ, 2008).

Footnote 4: Lianos (2010), "Judging Economists": Economic expertise in competition litigation: a European view, in Lianos & Kokkoris (Eds.), The Reform of EC Competition Law (Kluwer, 2009) 185-320.

Our team

Professor Ioannis Lianos

Research project initiator and coordinator

Ioannis Lianos is Professor in Competition Law and Public Policy at the Faculty of Laws, UCL in London and the Gutenberg Research Chair at the Ecole Nationale d’Administration (ENA) in France. He is the founder and Director of the Centre for Law, Economics and Society (CLES) at UCL Laws and the associate executive director of the Jevons Institute of Competition Law & Economics at UCL.

He is a visiting Professor in competition and intellectual property law at the Universities of Chile in Santiago, the University of Strasbourg and a fellow at the Centre for Law & Economics at the Australian National University. He has previously been an Emile Noel Fellow at the Jean Monnet Centre at New York University School of Law and a fellow at the Boalt Hall School of Law, University of California, Berkeley.

His primary research interest lies in European competition law, global competition law & policy, economic evidence and the legal system, law, economics and sociology. Ioannis is a Non-Governmental Advisor (NGA) at the International Competition Network (ICN) since 2009, a research partner to UNCTAD in competition law and policy since 2010, an elected member of the advisory board of the American Antitrust Institute since 2010.

He is a member of the advisory board of many Institutes active in the area of competition law and policy globally and a senior editor in many specialised journals in this area and is also the co-editor of the Global Competition Law & Economics series.

He has published extensively books and articles in various languages and leading academic journals in competition law and policy, regulation, the intersection of law with economics, and EU law. In 2012 he was awarded the Philip Leverhulme prize for his seminal research on economic evidence. He is also a Laureate of the French Academy of Moral and Political Sciences (2005). 

Dr Christos Genakos

View Dr Genakos's profile

Christos is Assistant Professor (Lecturer) in the Economics Department at Athens University of Economics and Business. He received his Ph.D. in economics from the London Business School. After the completion of his doctorate he worked as Lecturer, Fellow and Director of Studies in Economics at Selwyn College, Cambridge University.

He holds a Masters degree in Economics from the University College London and a Bachelor’s in Economics from the National and Kapodistrian University of Athens, where he graduated top of his class. He is also a visiting researcher at the Centre for Economic Performance in the London School of Economics and Political Science.

His research focuses on industrial organization and applied microeconomics, with an emphasis on quantitative techniques for competition analysis and regulation. He has published in many leading international peer-refereed journals, such as the Journal of Political Economy, the Economic Journal, the Journal of the European Economic Association, the Academy of Management Perspectives and more

Contact us

Centre for Law, Economics and Society University College London. E-mail: laws.research@ucl.ac.uk


December 2013

Oxford University Press has agreed to publish Ioannis Lianos’ monograph on “Economic Evidence in EU Competition Law” the early months of 2015. The book will present the results of the first stages of the research project and will be the first empirical book length study of the integration of economic evidence in competition law in Europe.