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一般地说,检疫效益较难评价。因为人们无法确知如果没有植物检疫,会有多少病虫害传进来,其中又有多少会在新区立足。这是无法模拟的。关于第一项还是可以有点估计办法,那就是查阅口岸植检每年截获病虫害的批数。美国资料,1979年全国各动植物检疫所共截获作物病虫害9,556起,其中有些是比较危险的。关于第二项就更不好办。它牵涉到病虫害的适生性和环境条件这两个密切相关的问
In general, quarantine benefits more difficult to evaluate. Because people can not know how many pests and diseases will come in without phytosanitary measures and how many of them will gain a foothold in the new district. This is impossible to simulate. On the first item, there is still some way of estimating it. That is to check the number of pests that have been intercepted each year by the phytoplasty at the port. In the United States, 9,556 crop pests and diseases were intercepted by various animal and plant quarantine offices nationwide in 1979, some of which were more dangerous. On the second is even harder to do. It involves two closely related questions about the fitness and environmental conditions of pests and diseases