Additionality in U.S. Agricultural Conservation Programs
研究了美国农业保护计划中，通过支付支持农民自愿采用环保做法，但只有那些没有支付就不会被采用的做法才能带来额外的环境收益。利用倾向得分匹配分析农业资源管理调查数据，发现超过95%的田间外结构做法具有额外性，而不到50%的保护性耕作支付带来了额外采用。
Agricultural conservation programs aim to improve environmental quality by using payments to support voluntary adoption of environmentally sound practices. Supported practices, however, yield additional environmental gain only if they would not have been adopted without payment. We estimate additionality for selected practices using propensity score matching to analyze data from the Agricultural Resource Management Survey (ARMS). We find that greater than 95% of off-field structural practices (filter strips, riparian buffers) supported by payments are additional but that less than 50% of conservation tillage payments yield additional adoption. The effect of nutrient management payments varies across nutrient management practices and crops. <i></i>