Regulation at the source? Comparing upstream and downstream climate policies
本文用基于主体的模型比较了上游（化石燃料开采）和下游（排放产生）气候政策的表现，发现上游监管能提高化石燃料价格，在覆盖不全时也有利，且直接监管在上游更有效。
Climate policies can be applied either upstream, where fossil fuels are extracted, or downstream, where emissions are generated. Specific policy instruments can be defined for either level, and can take the form of a price signal such as through a tax, or a quantity limit such as through direct regulation or a permit market. In this study, we present an agent-based model to compare the performance of these different instruments and regulation levels. Since policy coverage is often limited, i.e. not all firms being under the regulator’s control, we also examine the impact of incomplete coverage on relative policy performance. Our analysis shows that only upstream regulation leads to an increase in fossil fuel prices, which is benefitial under limited coverage as it also affects firms not directly affected by the policy instruments; that prices under quantity-based regulation can decline after an initial peak, stabilizing at a lower level than under the tax; and that direct regulation is more efficient when applied upstream.