We analyse how market competition in a vertically differentiated polluting industry is affected by product variants that comply at different levels with «green» social norms. A green consumption behavior is considered as a byword of good citizenship. Consumer preferences depend on a combination of hedonic quality and compliance with social norms. Assuming that the high hedonic quality variant complies less with these norms than the low hedonic quality variant, we characterize different equilibrium configurations which appear as a result of both the intensity of such norms and the country-specific income dispersion. Then, we focus on the role that institutions may have in using these norms to reduce pollution emissions.