Another name changer here, and as my current name suggests, I am not up to date, but buffy re weighing up benefits etc
See Annex 5 of the HMT Green Book for detail
www.gov.uk/government/uploads/system/uploads/attachment_data/file/220541/green_book_complete.pdf
In summary (with caveat that I'm rusty on all of this) first you attempt to assess who benefits and how much. Then you look at the characteristics of the people affected.
For example, you attempt to assess how much benefit (and how much of the cost) accrues to people in each income quintile. You can then weight the benefits according to who* benefits, with a greater weight for benefits (and costs) that fall on poorer people.
These weights are based on the idea that extra resources gained or lost have a greater impact on poorer people than on richer people."Broadly, the empirical evidence suggests that as income is doubled, the marginal value of consumption to individuals is halved: the utility of a marginal pound is inversely proportional to the income of the recipient. In other words, an extra £1 of consumption received by someone earning £10,000 a year will be worth twice as much as when it is paid to a person earning £20,000 per annum." If you "decide not to use distributional weights to make an explicit adjustment, this decision must be fully justified" (page 93, Green Book)
For characteristics other than household income, e.g. gender, race, disability status etc, you don't do this numerical weighting exercise (largely I suspect because it would be impossible to reach agreement that, say, benefits for a woman are worth X more than the same benefits accruing to a man - whereas there are, perhaps surprisingly, conventions about income for the poorest quintile being worth x more than extra income for the richest quintile). But you are required to attempt to assess the impact on different groups, and take steps to mitigate.
Does that help answer the question you were asking?
- cost - this is the cost of the programme itself, nothing to do with who is paying taxes, but e.g. if a road is built the someone's land is taken up, someone's peace is disrupted, habitats destroyed, all that sort of stuff, plus and the money isn't being used for something else, so someone else isn't benefiting and this is counted as a cost too.