Abstract: Reducing carbon dioxide emissions is crucial for reducing the danger posed by climate change. There are factors for and against democracies in achieving these desired reductions. Using data from 150 countries, we estimate the marginal emission intensity (i.e., the change in per-capita carbon dioxide emissions for a unit change in per-capita income) across autocracies and democracies. We use regional waves of democratization and mean per-capita income of other countries in the region as instruments for democracy and per-capita income, respectively. Using these instruments, we obtain the causal estimate of the difference in marginal emission intensity and confirm that democracies have lower per-capita carbon dioxide emissions per unit increase in per-capita income compared to autocracies. Our results suggest that these benefits of democracies have occurred in recent decades, following the surge in public concerns about climate change and intergovernmental initiatives to reduce emissions. There is also evidence to suggest that strengthening rule enforcement and improving access to justice can be critical in decreasing carbon dioxide emissions.

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独裁对环境有害吗？来自两个世纪数据的全球证据

摘要：减少二氧化碳排放对于减少气候变化带来的危险至关重要。在实现这些理想的减少方面，有支持和反对民主的因素。我们使用来自 150 个国家/地区的数据，估算了独裁国家和民主国家的边际排放强度（即人均收入单位变化引起的人均二氧化碳排放量的变化）。我们使用地区民主化浪潮和该地区其他国家的平均人均收入分别作为民主和人均收入的工具。使用这些工具，我们获得了边际排放强度差异的因果估计，并确认民主国家与专制国家相比，每单位人均收入增加的人均二氧化碳排放量较低。我们的研究结果表明，随着公众对气候变化和政府间减排举措的关注激增，近几十年来民主政体的这些好处已经出现。还有证据表明，加强规则的执行和改善诉诸司法的机会对于减少二氧化碳排放至关重要。