The Impact of Political Institutions on Climate Policy Effectiveness : Cross-National Evidence from Two Decades

Despite the rise in national climate policies, current efforts remain inadequate to prevent the adverse effects of climate change. Evidence shows that only a small fraction of policies enacted over the past two decades have resulted in measurable emission reductions, underscoring the need to better understand what drives climate policy effectiveness. This study explores how political institutions shape the effectiveness of national climate policies, defined as the extent to which policies lead to reduced emissions. Analyzing over 1,000 mitigation policies across 41 countries from 1997 to 2021, the study applies recent advances in causal policy attribution to link institutional features to policy outcomes. Results from fixed and mixed effects regression models reveal that both higher levels of democracy and stronger government power are positively associated with policy effectiveness. While democracy correlates with a greater number of effective policies, it does not increase their proportion. In contrast, stronger government power increases both the number and share of effective policies. No significant effects are found for government ideology or corruption. These findings highlight the critical role of institutional context, especially democracy and government power, in enhancing climate policy outcomes.