This paper develops an endogenous growth model to study the decentralized equilibrium and the optimum conditions in an economy which uses polluting resources. The model includes two policy instruments, a subsidy to final consumption and an emissions tax. It also considers two forms of endogenous technical change, pollution-reducing knowledge and horizontal innovation. We show that, if the efficiency of knowledge to reduce emissions is sufficiently high, a higher output is compatible with lower emissions in both levels and growth rates. Additionally, if the two instruments are used together the economy may achieve a higher output and lower emissions since the subsidy may offset, at least partially, the negative tax effects.
