Question to the HM Treasury:

To ask the Chancellor of the Exchequer, whether he has recommended changes to the social discount rates that his Department applies; and whether those changes will be applied retrospectively to projects in the Government's Major Projects Portfolio.

The Green Book Social Time Preference Rate (STPR) or discount rate is applied by all government departments in the formulation of policy appraisal and has been 3.5% since 2003 following regular independent expert reviews. There are no forthcoming changes to the headline discount rate, which is regularly reviewed in line with the evolution of appropriate evidence in consultation with academic experts.

As set out in the Green Book Review 2020, HMT will however, be conducting an expert review into the application of the discount rate for environmental impacts. This review will scrutinise the current guidance on environmental valuation and discounting and investigate whether there is a case for using the same discount rate as currently applied to the valuation of life and health effects.