More than three decades ago, lawyers and economists met in Chicago for “the greatest gig in the sky” in the history of law and economics: the Symposium on “Efficiency as a legal concern”, where many of the most authoritative law and economic scholars of that time discussed the merit of adopting efficiency criteria in legal adjudication, and ended up digging quite thoroughly into the virtues and hidden traps of the Kaldor-Hicks criterion as a normative basis for deciding about complex and controversial legal issues. That was also the time in which scholars like Richard Posner, William Landes, George Priest and Paul Rubin – all in favor of replacing legal criteria in adjudication with Kaldor-Hicks efficiency – were challenged by others, such as Ronald Dworkin, Richard Epstein, Anthony Kronman, Duncan Kennedy, Charles Fried, Gerald O’Driscoll Jr. and Mario Rizzo, who considered that efficiency criteria could lead to potential distortions in the making of value judgments when adjudicating legal controversies.