The results in this paper show that a policy maker who ignores regional data and instead relies on aggregated integrated assessment models will strongly underestimate the carbon price and thus the required climate policy. Using a stylized theoretical model we show that, under the mild and widely-accepted assumptions of asymmetric climate change impacts and declining marginal utility, an Aggregation Dilemma may arise that dwarfs most other policy- relevant aspects in the climate change cost-benefit analysis. Estimates based on the RICE model (Nordhaus and Boyer 2000) suggest that aggregation leads to around 26% higher total world emissions than those from a regional model. The backstop energy use would be zero in aggregated versions of the model, while it is roughly 1.3% of Gross World Product in the regionally-disaggregated models. Though the policy recommendations from fully aggre- gated models like the DICE model are always used as a benchmark for policy making, the results here suggest that this should be done with the reservations raised by the Aggregation Dilemma in mind.

中文翻译：

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气候变化政策评估中的聚集困境

本文的结果表明，忽略区域数据而依赖于汇总的综合评估模型的决策者将严重低估碳价，从而低估了所需的气候政策。使用程式化的理论模型，我们表明，在气候变化影响不对称且边际效用下降的温和且广泛接受的假设下，可能出现聚集困境，使气候变化成本收益分析中的大多数其他与政策相关的方面相形见war。根据RICE模型进行的估算（Nordhaus和Boyer，2000年）表明，聚集导致的世界总排放量比区域模型高约26％。在该模型的汇总版本中，支持能源的使用为零，而在按地区分类的模型中，其能耗约为世界生产总值的1.3％。