1 Some Law & Economics of the Class Action Ejan Mackaay Fellow, Cirano Emeritus Professor of Law, Université de Montréal ejan.mackaay@umontreal.ca ejan.mackaay@cirano.qc.ca pubished as: Mackaay, Ejan, Some Law and Economics of the Class Action, in: The Class Action Effect/ L'effet de l'action collective, Catherine Piché (ed.), Cowansville, Éd. Yvon Blais, 2018, pp. 205-228 ABSTRACT ...................................................................................................................................... 1 INTRODUCTION .............................................................................................................................. 2 I ON THE ECONOMICS OF ACCESS TO JUSTICE ..................................................................... 4 A. Some Broad Avenues for Increasing Means.................................................................. 5 B. Some Broad Avenues for Reducing Costs ..................................................................... 6 II THE CLASS ACTION AND ITS SPECIFIC TRANSACTION COSTS ........................................ 7 A The Class and its Members ............................................................................................. 8 B Ensuring that Class Counsel Act in the Interests of Class Members ............................ 10 C Payout ........................................................................................................................... 11 III CLASS ACTION AND OTHER FORMS OF REGULATION .................................................... 13 A. Class Actions as a Regulatory Approach ..................................................................... 13 B. Direct Regulation to Control Behaviour ........................................................................ 14 C. Criminal Law as a Regulatory Approach ...................................................................... 15 CONCLUSION ................................................................................................................................ 16 BIBLIOGRAPHY ............................................................................................................................ 17 Abstract Class actions aim to bring economies of scale to bear on legal proceedings, by joining cases that have a common cause of action against a common defendant into a single lawsuit leading to a judgment or settlement that binds the entire class. Legal procedures, lawyer time, evidence by experts and court resources are thus all used once for all, rather than multiple times during individual lawsuits.