A straightforward calculation shows that mitigation is better than business as usual – that is, the present value of the benefits exceeds the present value of the costs – for any social rate of time preference less than 8.5%. No estimate of the pure rate of time preference, even by those who believe in relatively strong discounting of the future, has ever approached 8.5%.
直接的计算显示减排比执行照常的政策要好，就是说，利益的当前价值超过了代价的当前价值——对于任何低于8.5%的社会时间偏好率而言。但是，还没有出现预计社会时间偏好率会接近8.5%的情况，即便对于那些认为对未来应该打相对很大的折扣的人而言也是如此。