Uncertain about uncertainty in pest risk analysis

摘要

Twenty years after the World Trade Organization Agreement on the Application of Sanitary and Phytosanitary Measures (the SPS Agreement) came into force for most countries, we have the opportunity to reflect on its implementation in practice and focus onkey challenges that countries have experienced. A central tenet of the SPS Agreement is that measures affecting trade are technically justified based on scientific principles and evidence of risk. This emphasis on evidence has resulted in risk analysis and decision making processes that largely ignore the role of uncertainty or respond to it inconsistently and ambiguously. The lack of discipline on the role of uncertainty in the SPS framework has resulted in wide-ranging interpretations that provoke trade tension, including formal disputes. A history of jurisprudence emanating from SPS-based disputes in the WTO provides useful insights into the most troublesome aspects of the relationship of uncertainty to evidence in risk analysis and decision making,including; (1) the potential for biasing risk conclusions, (2) the possibility to invoke precaution as a guiding principle, (3) the "rational relationship" between risk and the strength of measures, and (4) the distinction between the possibility and probability of adverse events. The lessons learned from these challenges help to translate the conceptual background of the SPS Agreement into practical terms and begin to better define appropriate disciplines on the interpretation of uncertainty.