This dossier has taken us through a conceptual discussion of the issues surrounding reasoning in international arbitration to a discussion of practical aspects of reasoning that affect the practice of arbitration and its users. The authors ask should/if, and how, reasons be stated in various contexts. And a common thread through the chapters is the issue of legitimacy— reasoning, the lack or insufficiency thereof, impacts not only the specific recipients of an award, but can impact the legitimacy as a means of dispute resolution, particularly in the context of investment arbitration. But weighing against this pull for more may be the arbitral mantra of efficiency.

As a preliminary matter, reasons are stated as a justification for the arbitrators, the parties, the courts, and institutions. And sometimes there can be inconsistencies in what these constituents require (efficiency vs. detailed explanations). We also examine the standard of review to be applied to the duty to state reasons. In terms of substance, it is important for parties to know that all arguments have been considered, but we are reminded that neither the NY Convention or the UNCITRAL Model Law have as a ground for setting aside the failure to state reasons.

Further, civil law and common law arbitrators have similar concerns regarding the complexity of facts and of law, the importance of writing to refining reasoning, concern for the losing party, and, the legitimacy of the award. There is, however, some divergence—in concern about challenges to awards (civil law arbitrators care more) and legitimacy of the process rather than of the award itself (common law lawyers care more).

The story that a reasoned award tells is critical in the context of investment arbitration, simply because of the sheer numbers of people affected by an award.

And what do users of arbitration want? Not surprisingly, reasoning is a demonstration of the legitimacy of the award, evidence of the arbitrators’ comprehension, and evidence that due process has been respected.

Although poor reasoning is not necessarily a reason for annulment, as elsewhere, there are certain minimum requirements (proof that facts, arguments, and evidence were considered) to satisfy a party’s right to due process.

Of primary importance for users are valid and enforceable awards—that is, capable of withstanding the scrutiny of court control. But enforcementproof reasoning also has to be convincing. The reasoning must be convincing to the parties, but also in order to withstand public policy scrutiny.

The call for "better" reasoning responds to calls for greater legitimacy in reasoning in both investment and commercial arbitration, from various audiences—some direct users, and some indirect users of arbitration. But there is a tension for arbitrators—the tension of efficiency, and what reviewing courts may actually require. Nonetheless, reasoning has such an impact, often beyond the principal litigants, that we can conclude from the contributions in this dossier that it may be time to outline certain basic standards for reasoning.