Exact optimal paths are calculated for a closed economy with human-made capital, non-renewable resource depletion and exogenous technical progress in production, hyperbolic utility discounting, and (possibly) hyperbolic technical progress. On its optimal path, generally, welfare-equivalent...

We compare three different views on the long run efficiencies of emission taxes which include thresholds, and of tradable emission permits where some permits are initially free. The differences are caused by different assumptions about whether thresholds and free permits should be subsidies...

A theoretical, representative agent economy with a depletable resource stock, polluting emissions and productive capital is used to contrast environmental policy, which internalises externalised environmental values, with sustainability policy, which achieves some form of intergenerational...