Pollution and Environmentalists’ Participation in Emissions Trading Systems^*

In this paper, we show that the participation by an environmental group in a permit market does not necessarily result in more investment in abatement or even less pollution. There is a U-shaped relationship between the emission per unit of output and the extra weight given by the environmental group to the reduction of emissions. For high values of this weight, firms invest less in abatement but also produce less. For lower values, firms invest more in abatement but also produce more, which may result in higher emissions levels.