Highlights :

 Abstract :
The paper deals with the equivalence between taxation and emission permits according to different viewpoints: the first one sets prices, the second one quantities. But equivalence is more formal than substantial: taxation is the generating fact, the market of permits does not exist spontaneously. Its price is unstable because supply is not independent from demand. It is manipulatable either ex ante when free allowances are allocated or ex post during the period of compliance through Walrasian tatonnement. A real economic determination of prices exists only when there are unit taxes or penalties on emissions exceeding the quotas. In order to avoid these drawbacks, pay-as-bid auctions must be used and free allowances avoided. Taxation or the price of emission permits are the real option value of changing techniques. An assignment rule is proposed : taxes are assigned to reduce average emissions and permits to reduce marginal emissions. In order to transform the cost into a real change of techniques, it is necessary to finance the sector of research and development of an amount greater than the taxes levied on pollution, which serve at paying the rent of innovation. These extra subsidies are used to move factors of production as capital from industry towards the innovation sector. The tax equivalence is ternary and concerns the taxes on pollution, capital and energy, because extracting fossil fuels is similar as innovation. Decentralization through market schemes induces that depollution has a marketable cost.

 Keywords : Equivalence | Droits d'émission échangeables | Fiscalité de l'environnement

 JEL : E61, E62