The economic costs of non-indigenous species (NIS) are a key factor for the allocation of efforts and resources to eradicate or control baneful invasions. Their assessments are challenging, but most suffer from major flaws. Among the most important are the following: (1) the inclusion of actual damage costs together with various ancillary expenditures which may or may not be indicative of the real economic damage due to NIS; (2) the inclusion of the costs of unnecessary or counterproductive control initiatives; (3) the inclusion of controversial NIS-related costs whose economic impacts are questionable; (4) the assessment of the negative impacts only, ignoring the positive ones that most NIS have on the economy, either directly or through their ecosystem services. Such estimates necessarily arrive at negative and often highly inflated values, do not reflect the net damage and economic losses due to NIS, and can significantly misguide management and resource allocation decisions. We recommend an approach based on holistic costs and benefits that are assessed using likely scenarios and their counter-factual.

非本土物种（NIS）的经济成本是分配努力和资源以消除或控制有害入侵的关键因素。他们的评估具有挑战性，但大多数都存在重大缺陷。其中最重要的是： (1) 包括实际损害成本以及各种辅助支出，这些支出可能表明也可能不表明 NIS 造成的实际经济损失；(2) 纳入不必要或适得其反的控制举措的成本；(3) 纳入有争议的 NIS 相关成本，其经济影响值得怀疑；(4) 仅评估负面影响，忽略大多数国家创新体系直接或通过其生态系统服务对经济产生的积极影响。这种估计必然会得出负值，而且往往是高度夸大的值，不能反映NIS造成的净损害和经济损失，并且可能会严重误导管理和资源分配决策。我们建议采用一种基于整体成本和收益的方法，该方法使用可能的场景及其反事实进行评估。