What explains the emergence and diffusion of green bonds?

There is growing recognition that financing low-carbon energy and environmental transitions will require the innovation of new financial products. Yet current understanding of the conditions under which environment-focused financial innovations emerge and diffuse remains limited. This paper seeks to narrow this gap. Novel to the literature, we conceptualise financial innovation by synthesising insights from several conceptual frameworks previously used to understand technological innovation and sustainability transitions. Empirically, the paper focuses on the case of green bonds, which have been deployed to (re)finance a wide range of energy- and environment-related projects. Our analysis is based on a combination of semi-structured interviews, document analysis and observations from conferences. We show that many of the same processes, influences and dynamics identified in technology-inspired frameworks have played an important role in the upwards innovation trajectory of green bonds. These include: the activities of various intermediaries and entrepreneurs; a set of largely self-reinforcing processes such as learning and legitimation; and wider contextual developments creating a more favourable selection environment for sustainability-themed, fixed-income financial products. Our analysis additionally suggests that the scaling-up of green bonds depended on the specific design and implementation of the product itself and the growing involvement of emerging economies on the supply-side.