Private Enforcement of Antitrust Law in Japan: An Empirical Analysis

8 Competition Law Review 7-28

22 Pages Posted: 14 Jul 2012 Last revised: 29 Mar 2013

See all articles by Simon Vande Walle

Simon Vande Walle

University of Tokyo - Graduate Schools for Law and Politics

Date Written: February 1, 2012


This article assesses the role of private antitrust litigation in Japan through an empirical analysis. Based on data concerning actions for damages and injunctive relief in the post-war era, the article gauges how much private antitrust litigation has contributed to the deterrence of antitrust violations, compared to public enforcement by the Japan Fair Trade Commission. It also evaluates to what extent private antitrust litigation has resulted in compensation for those harmed by antitrust violations. Finally, it compares the level of private enforcement in Japan with levels in Europe and the United States.

The article includes findings on (1) the number of private antitrust actions, (2) the types of antitrust infringements invoked (bid-rigging, cartels other than bid-rigging, monopolization and unfair trade practices), (3) the success rate of antitrust litigation, (4) the magnitude of the damages awards and settlements, (5) the proportion of stand-alone versus follow-on cases, and (6) the kind of plaintiffs that have recovered damages.

Based on these data, the article concludes that, despite the dramatic increase in the number of filings in the past two decades, private antitrust litigation’s role in generating deterrence and compensation has remained limited. In fact, the only area in which private lawsuits really played a systemic role was bid-rigging. In bid-rigging cases, local citizens, acting as “private attorney-general”, used a unique litigation mechanism to recover substantial amounts on behalf of local governments. In addition, public entities frequently seek and obtain significant damages from bid-riggers. Through these actions, local governments and government agencies have recovered tens of billions of yen. By contrast, in cases other than bid-rigging, aggregate antitrust recoveries have been much more modest. Businesses have recovered comparatively little and consumers virtually nothing.

Suggested Citation

Vande Walle, Simon, Private Enforcement of Antitrust Law in Japan: An Empirical Analysis (February 1, 2012). 8 Competition Law Review 7-28, Available at SSRN:

Simon Vande Walle (Contact Author)

University of Tokyo - Graduate Schools for Law and Politics ( email )

7-3-1 Hongo Bunkyo-Ku
Tokyo, 113-0033


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