Arbitration supplements the judicial system, it is often said, by providing relatively cheap, speedy, and expert decisionmaking. But arbitrators are not generalist judges, and so typically are not as expert in the law. They are thus prone to make mistakes, or at least presumptively more prone to do so than judges. A legal system, like that of the United States, that has a policy of supporting arbitral dispute resolution must decide on a level of scrutiny to apply to arbitral interpretations of law when they are challenged before courts. The modern trend is to choose a fairly deferential level of review: most arbitration statutes and the United Nations Convention on the Recognition and Enforcement of Foreign Arbitral Awards3 do not allow judicial review for errors of law. Only particularly egregious arbitral errors lead to the setting aside or nonenforcement of an award.