Determinants of herbicide use in rice production in the Philippines
研究了菲律宾稻农采用除草剂及使用量的决定因素，发现农户年龄、家庭规模、灌溉、除草剂价格、收入、信贷、土地所有权、农场面积和作物建立方法等均有显著影响，对制定减少过度使用除草剂或推广替代除草方法的政策有参考价值。
Abstract This study identifies farm‐specific and market factors affecting the adoption of herbicides and the level of herbicide use by rice farmers in the Philippines. This requires the application of a modified version of Heckman's two‐step method to estimate a random‐effects double‐hurdle model for unbalanced panel data. The age of the farmer, household size, and irrigation use are significant determinants of the decision of farmers to adopt herbicides as an alternative to manual weeding, while economic variables such as the price of herbicides, total income, and access to credit determine the level of herbicide use. Determinants of both adoption and level are land ownership, farm area, and the method of crop establishment. These results are potentially relevant when designing policies to reduce excessive herbicide use or to encourage the adoption of alternative weed control methods such as integrated weed management.