Towards a public sustainable finance paradigm for the green transition

Sustainable finance is often discussed as a solution to the climate crisis, but its impacts are limited and its discourse focuses on mobilising private investments through public de-risking, without considering direct government action. We argue that this is due to an implicit reference to mainstream economic theory assuming that an active state leads to time inconsistency problems and crowding-out effects. However, these assumptions have been sufficiently refuted as public investments may actually crowd-in private capital. We therefore propose a paradigm shift towards what we call Public Sustainable Finance, aimed at empowering the role of the state in the green transition on the discursive, policy, and political economy levels. Studying the case of Germany, we show how Public Sustainable Finance can be introduced despite tight fiscal regimes. To this end, we propose that the Climate- and Transformation Fund be given its own borrowing powers. By borrowing an average of 23 billion euros annually from 2024 to 2030, the existing financing gap that has been exacerbated following the November 2023 constitutional court ruling can be closed, enabling a more rapid and effective green transition.