  Prioritarianism holds that the moral value of achieving a benefit for an individual (or avoiding a loss) is greater, the greater the size of the benefit as measured by a well-being scale, and greater, the lower the person's level of well-being over the course of her life apart from receipt of this benefit. Well-being weighted by priority as just specified is sometimes called “weighted well-being.” To this account of value the prioritarian adds the position that one ought to act, and institutions should be arranged, so as to maximize moral value as defined. (See chapter 2 of Scheffler 1982, Weirich 1983, Parfit 1997).