In a new paper, Mark Daku and Krzysztof Pelc argue that certain countries have more influence than others in shaping the language of WTO panel and AB rulings:
We argue that power is most likely to be exercised at the margins. In the case of the WTO, such power can take on two forms: it can be proxied by wealth, or by capacity. The belief we want to test in each case is that more powerful countries, either in terms of wealth or legal capacity, are better able to get the court to adopt the language of their submissions in its final rulings. We begin by visualizing the variation in influence across countries in the simplest way possible. Figure 2 shows a dot plot of the average proximity of countries’ submissions to the final ruling. We consider the 15 most frequent users of dispute settlement, to avoid having countries with a single submission skewing the results. This figure makes no distinction as to the role countries were playing in the dispute, and mixes in the panel and AB stage.
This quick snapshot of influence appears to match expectations: submissions by the United States and the EU appear as most influential. In fact, US submissions appear significantly more influential than any other country. ...
On the other hand, this doesn't seem to help them with the result:
The premise of this article is that countries hold more influence at the margins. Put in terms of the incentives of an international court, because the content of rulings is harder to scrutinize than “who wins”, politically savvy judges are more likely to defer to country interests in the content of the ruling than in its direction. For the sake of comparison, we thus show the effects of legal capacity on the direction of the verdict itself. To do this, we code the direction of every claim in every WTO dispute from 1995 to 2013. All told, panels have delivered 1,429 findings on 820 individual claims. We first collapse these findings at the claim level, and then collapse claims at the dispute level, to obtain the number of claims won by the complainant. We divide this number by the total number of claims ruled on, to obtain the percentage of claims won by the complainant, which varies from 0 to 1; its mean is 0.74 for panel rulings, and 0.69 for appellate rulings. The results are shown in Table 4, where we estimate the odds of a pro-complainant verdict, using the same explanatory variables as in our estimation of influence.
What Table 4 shows is that capacity, however measured, does not help countries “win cases”.