Can uncertainty justify overlapping policy instruments to mitigate emissions ?
This CIRED article constitutes a new contribution to the analysis of overlapping instruments to cover the same emission sources. Using both an analytical and a numerical model, we show that when the risk that the CO2 price drops to zero and the political unavailability of a CO2 tax (at least in the European Union) are taken into account, it can be socially optimal to implement an additional instrument encouraging the reduction of emissions, for instance a renewable energy subsidy…