Alternative Models of Res Judicata in Class Actions a Comparative Law & Economics Approach

After the upsurge of class actions in North America, since the amendment to Federal Rules of Civil Procedure (FRCP) of 1966, this initially idiosyncratic American sort of litigation has pervaded procedural systems of countries of Civil Law tradition in the following decades. Its reception has not been uniform nor easy nonetheless. It is still, moreover, a work in progress.The rise of class lawsuits is commonly acknowledged as a product of the opt-out rule adopted by the amended Rule 23 FRCP. It is also a consequence of the conclusive effect of settlement or judgment on hypothetical subsequent claims, throughout res judicata and collateral estoppel nonetheless.Civil Law jurisdictions, as France, Brazil and Argentina, in turn, include in their class action schemes variations, precisely on those matters, which give an interesting leeway for study.Our findings suggest that there is some room for improvements in those recent Civil Law schemes of class actions. Some of their peculiar innovations may look questionable but scarcely significant in practice. However, that empirical irrelevance may derive only from pre-existing chronic malfunctions in procedural systems that include them. Paradoxically, a betterment on the latter failures would make the negative impact of the analyzed variants significant on social cost