Effective climate policies for ‘all seasons’: novel evidence from 40 countries

As governmental climate policy efforts are expanding, evaluating their effectiveness has become increasingly challenging due to numerous coexisting policies that complicate isolating individual impacts. How can we assess the effectiveness of individual climate policies during periods of continuous policy expansion? This paper explores methodologies designed to explicitly model all climate ‘policy parameters’. By integrating Bayesian priors, we regularize the estimation model, incorporating additional information to ensure that only policies meeting a certain threshold of evidence are considered. Applying our methodology to the analysis of 47 different climate policies in 40 countries over 32 years (1990–2022) in four policy sectors (1,737 individual policies), we identify those policies being consistently effective under various contextual conditions and examine their emission reduction potential in greater detail. Our findings provide decision-makers with insights into the most likely effective climate policies and offer scholars an innovative tool with which to evaluate policies within expanding policy mixes.Key policy insightsThe paper introduces a new methodological toolkit that enables a comprehensive analysis of climate policies, adaptable to examine various policy areas amid policy growth.The paper presents a list of essential climate policy measures that effectively enhance climate ambitions across all mixes, serving as a guide for policymakers.The paper provides a country-specific overview identifying areas with the highest potential for additional climate action, offering policymakers a clear path to improve their country’s climate performance.