Some paradoxical issues about negociating an international carbon tax

To date, debates on economic incentives apt to coordonate Greenhouse Gases emissions abatement policies focused mainly on an international uniform carbon tax and this for two type of reasons : the classical result of the unicity of a Pigouvian tax the simplicity of its implementation. This paper presents a theoretical model which captures the equity-efficiency issues involved in these debates. It demonstrates that an efficient allocation of the abatement efforts will be achieved by personalised taxes or by uniform tax applied together with compensations across countries. A numerical exercise which accounts for the controversies about many parameters underlying the negotiation helps deriving some policy-oriented conclusions for the implementation of the Berlin Mandate, and the follow-up of Kyoto Agreement.