Florian Wagener (ASE, UVA) - Markov-perfect equilibria in differential games, with an application to climate policy

We introduce discontinuous Markovian strategies for differential games. The best response correspondence uniquely maps almost all profiles of opponents’ strategies back to the strategy space. We thus make Markov-perfect equilibria (MPE) in a wide class of differential games well-behaved, resolving a long-standing open problem. We provide a readily applicable necessary and sufficient condition for best responses and MPE. We demonstrate our methods in a canonical model of non-cooperative mitigation of climate change. Our approach provides novel, economically important results: we obtain the entire set of symmetric Markov-perfect Nash equilibria, and demonstrate that the best equilibria can yield a major welfare improvement over the equilibrium which previous literature has focused on. International climate negotiations should be seen as being about coordination on good equilibria, rather than about bargaining over the limited surplus available in a dynamic prisoner’s dilemma.

Ann-Kristin Grosskopf (ABS, UvA) - Politics of sustainability reporting: Evidence from NGO involvement

NGOs have become an increasingly important actor in the development of sustainability disclosure rules, and public consultations from 2016 to 2023 reveal how they engage in this process. But their participation remains far lower than that of corporate preparers, creating an imbalance in who provides input to emerging standards. Therefore, we analyze NGO involvement and their preferred reporting obligations using EU, EFRAG, and ISSB consultations, NGO statements, and interviews. We find that NGOs participate selectively but consistently advocate broad, high-ambition disclosure requirements, especially for high-risk sectors and high-impact topics. Their positions often diverge from corporate preparers yet align with financial preparers. While some demands initially informed the CSRD, subsequent political changes, particularly the Commission’s Omnibus amendments, diluted key provisions and reduced NGOs’ willingness to invest their technical expertise in the standard-setting process.