Evaluating the effects of policy innovations: Lessons from a systematic review of policies promoting low-carbon technology

We report on an original systematic review of 165 empirical, ex post studies examining policies that promote the development and use of low-carbon technologies. Policy is defined broadly to include diverse instruments (e.g., eco-labels, voluntary agreements, emission credits, and taxes), developed, administered, and promoted by state and non-state actors (e.g., cities, states, corporations, business associations, and non-governmental organizations) that are relevant to climate change. By disaggregating policy designs, we are better able to understand the features of policies (e.g., instrument type, regulatory target, built-in flexibility) associated with effectiveness and the trade offs different features create among evaluation criteria. Our analysis, thus, sheds new light on the final and arguably most important criterion of policy innovations - the extent to which they have lasting consequences.