ABSTRACT

Inter-municipal cooperation in metropolitan areas has been previously shown to save costs, but can it also improve environmental outcomes? The existing empirical evidence is largely based on single case studies and does not allow to ascertain the net effect of cooperation. We develop a three-level mixed-effects linear model to conduct a systematic large-n study testing the impact of cooperation in transportation on CO₂ transport emissions. We use a novel dataset covering over 200 metropolitan areas in 16 OECD countries. The findings demonstrate that both fragmented and consolidated metropolitan governance structures are equally inefficient in delivering a reduction in CO₂ transport emissions. Further, without functional enforcement mechanisms, mitigation policies fail to have a positive effect on environmental outcomes. Inter-municipal cooperation in metropolitan areas facilitates coherence and widespread enforcement and emerges as a crucial factor explaining the reduction of CO₂ transport emissions. Effects of metropolitan cooperation on transportation are magnified by the presence of national environmental mitigation policies.

摘要

大都市地区的市际合作以前已被证明可以节省成本，但它还能改善环境成果吗？现有的经验证据主要基于单一案例研究，无法确定合作的净效应。我们开发了一个三级混合效应线性模型来进行系统的大 n研究，测试交通合作对 CO ₂交通排放的影响。我们使用了一个新的数据集，覆盖了 16 个经合组织国家的 200 多个大都市地区。研究结果表明，分散和统一的大都市治理结构在减少 CO _{2方面同样效率低下}运输排放。此外，如果没有有效的执行机制，缓解政策就无法对环境结果产生积极影响。大都市地区的城市间合作促进了连贯性和广泛的执法，并成为解释 CO ₂运输排放减少的关键因素。国家环境缓解政策的存在放大了大都市合作对交通的影响。