Evaluating environmental effects of adopting automatic milking systems on Norwegian dairy farms
提出基于生态效率的新方法，评估挪威奶牛场采用自动挤奶系统带来的结构性和行为性二次效应，发现该系统减少每头牛劳动时间并扩大牛群规模，对生态效率的影响因牧场而异。
Abstract We present a novel procedure based on eco-efficiency for assessing farm-level effects of technology adoption while considering secondary effects. Secondary effects are defined as structural and behavioural adaptations to technology that may impact environmental, social or economic outcomes. We apply the procedure to automatic milking systems (AMS) in Norway and find that AMS induces secondary effects, most strongly by decreasing labour per cow and increasing herd sizes. For estimating effects of AMS we employ a novel causal machine learning approach. AMS induce heterogenous effects on eco-efficiency, negatively associated with herd expansion and labour per cow.