World Trade Organization panels are regularly required to address specifically economic evidence and arguments when resolving disputes. Economic arguments provide the basic foundations for many disputes, and parties are proving increasingly willing to contest the facts underlying those arguments. Despite this, panels have often failed to engage satisfactorily with economic reasoning. The deficiencies in panels’ reasoning have been exacerbated by their refusal to seek information and advice from independent economic experts. This approach is neither necessary nor productive. It undermines the epistemic legitimacy of individual panel reports and the political legitimacy of the dispute settlement system more generally. More careful and rigorous panel engagement with economic evidence, as assisted by independent experts acting within appropriate limits, would go some way to reducing this legitimacy deficit while improving the accuracy and finality of the dispute settlement system.