Does the choice of numeraire matter in cost-benefit analysis?

Brekke [Brekke (1997) Journal of Public Economics 64, 117-123] claims that using money as the numeraire in cost-benefit analysis "is systematically favourable to those who value money the least, relative to alternative numeraires." This note attempts to show that the outcome of a properly undertaken cost-benefit analysis is independent of the choice of numeraire. However, since the marginal social utility of income (or, say, an environmental good) is unobservable, one faces a formidable problem in assessing the social profitability of a project which affects more than a single person. (C) 1998 Elsevier Science S.A. All rights reserved.