Efficiency of U.S. conservation-compliance program
研究了美国保护合规计划中强制要求生产者将土壤侵蚀降至每英亩7吨的做法，发现通过可交易土壤流失配额系统，不同土壤类型的边际控制成本可均等化，从而提升效率并节省社会成本。
ABSTRACT Under the conservation‐compliance program, most of the individual producers are forced to cut their soil erosion to 7 t per acre annually irrespective of the marginal cost of controlling soil erosion. In a system where coupons to a ton of soil loss were issued to producers and traded, the marginal cost of controlling soil loss within each soil type and across different soil types would be equalized. An instrumental variable procedure was used to determine the effect of soil erosion on net profits. The results for Iowa show that there is considerable difference in the marginal opportunity cost of controlling soil erosion between soil types. By assigning one ton of erosion to Iowa soil type Downs (5‐10% slope) instead of Clarion (2‐5% slope), there is a savings of $5.00 per acre for the society as a whole. The tradable coupon system is not only efficient, but will also bring in more land under soil conservation.