Discounting in the presence of catastrophic risk is a hotly debated issue, in particular with respect to climate change. Many scientists and laymen concerned with potentially catastrophic impacts feel that if an increase in the discount rate drastically increases the likelihood of catastrophic...

In an in_nite horizon optimal control problem, the Hamiltonian vanishes at the in_nite horizon, when the di_erential equation is autonomous. The integrand in the integral criterion may contain the time explicitly, but it has to satisfy certain integrability conditions. A generalization of...