Thanks to Meredith for suggesting this and Simon for setting it up.
The basic idea – expressed in a purely personal capacity - is in the article on the JIEL website and Simon has already summarised it, and I will not here repeat the details.
I think that Meredith and I agree on almost everything – there are considerations cutting both ways.
The essential point on which we may differ is that, in the particular circumstances of the WTO, I have difficulty seeing the value added of dissents, and given the damage to the system, on balance I conclude that dissents may not be such a good thing.
The starting point for the proposition that a dissent may have some value added would appear to be the notion that the dissent may have an inherent merit (on the substance). However, the dissenting view is already in the report (often a cut-and-paste of an executive summary directly prepared by the dissenting Member itself) and because, unusually in judicial systems, the report is adopted by a political body (the DSB) and the dissenting Member has the opportunity to explain its disagreement in the minutes, and often does. In some cases, the dissenting Member's views have even been disseminated in the same official DS document series (although one may question whether or not this is really consistent with the DSU). Thus, the dissent, whether or not merited, is already in the public domain. On the other hand, if the value of the dissent is its inherent authority (because it is authored by an adjudicator) as opposed to its inherent merit, then that would seem to confirm that there is also value – and indeed more value - in the authority of a unanimous judgment (which is authored by all three adjudicators).
Another consideration influencing my conclusion is undoubtedly the experience of building consensus within large organisations encapsulating very different views. Experience suggests that rational and reasonable exchanges of views almost always eventually lead to agreement – and not necessarily compromise. That must particularly be so in a judicial context like the Appellate Body, where the facts, evidence, claims and arguments are procedurally circumscribed (thus one cannot talk about everything indefinitely) and where one applies an agreed interpretative cipher (essentially, Articles 31 to 33 of the Vienna Convention). It also reflects the view that a great many WTO disputes are something of a foregone conclusion. The real dispute is not between the Members, but between constituencies within one Member, one domestic constituency having been "sold out" in the Green Room at the time of the negotiation, having swallowed an ambiguous text that an informed observer could have told them meant something else. This is not a bad thing – just an unavoidable part of using a legal process of legislation and adjudication to develop economic integration. Thus, from a rules based perspective, it is really not surprising that three adjudicators in the Appellate Body should systematically reach agreement.
If one does not see it in terms of rules, but rather in terms of power, then perhaps another way of looking at the problem is through the prism of Robert Axelrod's work on the Prisoners' Dilemma (The Evolution of Co-Operation, Robert Axelrod, Basic Books, 1984), which also chimes with the notion of comparative advantage in the context of trade. He describes how, over sustained periods, co-operation emerges, thrives and persists amongst self-interested actors without central authority. From this perspective, if benefit is measured in terms of the authority of pronouncements, a unanimous judgment corresponds to mutual co-operation and delivers the maximum "authority" benefit over time both for the system and for the individuals in their official capacities as WTO adjudicators. At the other extreme, three dissents (a prospect discussed in the article) corresponds to minimum benefit, and indeed would eventually imply the collapse of the DSU, the rules based system and the WTO. Finally, a single dissent might deliver a temporary personal pay-off for the dissenter, but is likely in the long term to lead to reduced benefits for the system as a whole, as well as the dissenter. I am not suggesting that the apparently optimal strategy of tit-for-tat is appropriate for a WTO adjudicator, but I do think that without the "forgiveness" feature of the tit-for-tat strategy unwarranted dissents risk to put the system into a downward spiral, and that this would likely stress intensely the process by which adjudicators are selected. I think there is already some evidence of this in the current difficulties surrounding panel composition. Thus, I don't see these developments as a sign of maturity – more as a nasty rash to be cured by abstaining from gratuitous dissent, in favour of faithful co-operation with one's long term partners.