Cost Benefit Analysis and Utility

Cost Benefit Analysis:

"Formal benefit cost analysis counts everyone’s gains and losses equally. But common sense and the principle of diminishing marginal utility agree that a dollar’s worth of gain is more valuable to someone with few dollars than it is with someone with many. Obviously, taking $1 each from 900,000 poor people to give $1 million to a hedge-fund billionaire doesn’t reflect a social gain, but a formal benefit-cost analysis will show that it does: after all, the net benefit is $100,000. Thus gains and losses should be adjusted by (at least) dividing each gain or loss by the income or wealth of the person bearing it, so that a $20 gain to a family with an income of $20,000 weighs as a heavily as a $10,000 gain to a family with an income of $1 million."