摘要：Under the set-up of Weitzman (1974), we examine the relative environmental efficiency of price (i.e., emission tax)
and quantity (i.e., emission cap) policies given the expected net benefits of emissions no less than some fixed value.
We discover that quantity policies are more environmentally efficient than price policies regardless of relative
steepness of emissions' marginal benefit and marginal cost functions. However, if the constraint of minimum expected
net benefits of emissions is not considered, both price and quantity policies are equally efficient.
