Pollution, mortality and time consistent abatement taxes

We study dynamically consistent policy in a neoclassical overlapping generations growth model where pollution externalities undermine health but are mitigated via tax-financed abatement. With arbitrarily constant taxation, two steady states arise: an unstable ‘poverty trap’ and a ‘neoclassical’ steady state near which the dynamics might either be monotonically convergent or oscillating. When the planner chooses a time consistent abatement path that maximises a weighted intergenerational sum of expected utility, the optimal tax is zero at low levels of capital and then a weakly increasing function of the capital stock. The non-homogeneity of the tax function along with its feedback effect on savings induces additional steady states, stability reversals and oscillations.