The International Handbook of Competition – Second Edition
Show Less

The International Handbook of Competition – Second Edition

Edited by Manfred Neumann and Jürgen Weigand

The book aims to further our understanding of how economic reasoning and legal expertise complement each other in defining the fundamental issues and principles in competition policy. In specially commissioned chapters the book provides a scholarly review of economic theory, empirical evidence and standards of legal evaluation with respect to monopolization of markets, exploitation of market power and mergers, among other issues.
Buy Book in Print
Show Summary Details
You do not have access to this content

Chapter 7: Defining antitrust markets

Rachel Griffith and Lars Nesheim


The definition of markets has long been a central feature of antitrust investigations. The substantive decision in many cases stands or falls on the precise market definition selected. The recent literature has questioned whether the focus on market definition can sometimes detract from the real question at hand, which is whether a merger or firm behaviour harms consumers. Nonetheless, market definition continues to play an important role because the computation of market shares matters in antitrust cases for at least two reasons. First, market shares are often used to help establish jurisdiction or, more generally, to sort out priorities for antitrust agencies. Merger regulations usually specify a threshold level of market share which triggers an investigation for mergers above a given size; investigations into various monopolistic abuses are usually centred on the leading firms in a market, and, in most cases, the ability of an antitrust agency to initiate an investigation, or impose penalties at the end of it, depends on whether the (alleged) offending firm enjoys a position of market “dominance”; i.e. enjoys a large market share.

You are not authenticated to view the full text of this chapter or article.

Elgaronline requires a subscription or purchase to access the full text of books or journals. Please login through your library system or with your personal username and password on the homepage.

Non-subscribers can freely search the site, view abstracts/ extracts and download selected front matter and introductory chapters for personal use.

Your library may not have purchased all subject areas. If you are authenticated and think you should have access to this title, please contact your librarian.

Further information

or login to access all content.