Introduction

Commercial disputes brought under the auspices of the WTO are becoming more and more complex. As a consequence of the increasingly judicial nature of the WTO dispute settlement system, parties submit increasingly sophisticated legal, but also – and this is a relatively new trend – factual arguments. By their very nature, instruments such as the Agreement on Sanitary and Phytosanitary Measures (SPS Agreement) or the Agreement on Technical Barriers to Trade (TBT Agreement) mean that WTO panels have to adjudicate disputes entailing scientific issues. But disputes brought under the GATT 1994 have also raised contested scientific issues relating to human health and to the conservation of natural resources. More over, in the new ‘legalized’ WTO dispute settlement system, as opposed to the more ‘diplomatic’ procedures used under the GATT 1947, parties tend to increasingly dispute factual evidence.

Pursuant to Article 11 of the Dispute Settlement Understanding (DSU), panels are called upon to ‘make an objective assessment of the matter before it, including an objective assessment of the facts of the case’. As we shall see, WTO panels enjoy a broad margin of discretion in the collection and appreciation of the evidence. This entails a corresponding responsibility to analyse this evidence in a critical and credible manner. More over, the Appellate Body does not review the facts of the case since appeals are limited to issues of law.