We need systematic examination of corporate responses to the EU ETS in several different industrial sectors to learn more about how the system works on the ground. Learning from previous experience is vital, since the EU has also identified the ETS as its key climate policy instrument for achieving its future goal of decarbonization, and because the system might come to serve as a governance model for other countries. This chapter outlines a broad analytical framework that will guide our empirical research into whether, how and why companies in different sectors have responded to the EU ETS. Approaching the questions posed in the first chapter takes us to various strands of the social science literature, including economics and political science.