Abstract：
Member states in the European Union (EU) implemented both ex ante coexistence regulations and ex post liability schemes to ensure that genetically modified (GM) and non-GM crops can be cultivated side by side without excluding any agricultural option. Although proportionate coexistence is best achieved if regulated in a flexible manner, most implemented coexistence regulations merely rely on rigid measures. Flexible coexistence regulations, however, would reduce the regulatory burden on certain agricultural options and avoid jeopardizing economic incentives for coexistence. Flexibility can be integrated at: (i) the regulatory level by relaxing the rigidity of coexistence measures in ex ante regulations, yet without offsetting incentives to implement coexistence measures; (ii) the farm level by recommending the use of pollen barriers instead of large and fixed isolation distances; and (iii) the national/regional level by allowing diversified coexistence measures, which are adapted to the heterogeneity of farming in the EU. Owing to difficulties of implementation, the adoption of flexible and proportionate coexistence regulations will inevitably entail challenges.
摘要：
欧盟（EU）成员国实施了事前共存法规和事后责任计划，以确保转基因（GM）和非转基因作物可以并排种植，而不排除任何农业选择。尽管如果以灵活的方式进行调节，最好实现成比例的共存，大多数实施的共存条例仅仅依靠刚性措施。灵活的共存规则，然而,将减轻某些农业选择的监管负担，并避免危及共存的经济动机。可以在以下方面整合灵活性：（i）通过放松事前法规中共存措施的刚性，但没有抵消实施共存措施的激励措施；(ii)通过建议使用花粉屏障而不是大的和固定的隔离距离来提高农场水平；(iii)通过允许多样化的共存措施来提高国家/地区水平，适应了欧盟农业的异质性。由于执行困难，采用灵活和相称的共存条例将不可避免地带来挑战。
