Linking technological innovation with mitigation cooperation in international environmental agreements

Mitigation and research and development (R&D) cooperation are central to international environmental agreements. However, their interaction in long-term self-enforcing settings remains unclear. We examine joint mitigation and R&D in an infinitely repeated game and characterize weakly renegotiation-proof equilibria. Linking technological cooperation to mitigation sustains large and stable coalitions. Contrary to the conventional view that technological spillovers weaken cooperation, spillovers increase welfare without reducing coalition size. Moreover, welfare gains come primarily from coalition expansion rather than high R&D investment. Numerical simulations illustrate how cooperative and unilateral R&D arrangements affect stability and efficiency.