The problem is not that cap and trade is an ivory-tower theory that cannot work in the real world; on the contrary, its performance surpassed expectations. In the 1980’s, it enabled lead to be phased out more rapidly than predicted and at an estimated annual savings of $250 million relative to the command-and-control approach.
设限+交易并是一个不切实际的象牙塔理论；相反，它的效果超出了预期。在1980年代它以超乎预计的速度淘汰了含铅燃料，并且估计比命令+控制政策每年节省2.5亿美元。同样，限制二氧化硫排放的成本甚至比设限+交易的支持者们在1995年前预估的还要低