Question to the HM Treasury:

To ask the Chancellor of the Exchequer, what his Department's policy is on providing support for infrastructure projects that have a negative net present value in their appraisals.

The Government published a new version of the Green Book in February. This ensures that government decisions are no longer based solely on single metrics, such as benefit-cost ratios or net present social values. They must instead take into account the full range of economic and social impacts that arise from the project.

The new Green Book makes clear that a proposal with a benefit-cost ratio of less than one (i.e. a negative net present social value) may still represent value for money. This may be the case, for instance, if the project has significant benefits that cannot be expressed in monetary terms and which therefore cannot be included in a benefit-cost ratio.