The facts that relative consumption concerns may give rise both to positional and environmental externalities, and that these two externalities are increasingly transboundary require us to derive an optimal commodity tax in an international framework. The corrective tax policy decided at a national level is found to fail to internalize all positional and environmental externalities. The optimal tax policy under an international cooperative framework reflects correction for both global positional and environmental externalities. In this broader framework, we also characterize the provision of pollution abatement as an additional policy instrument. The results show that relative concerns for one of the private goods do not lead to any modification of the policy rule for public abatement.