utilityu定義(續)

去除常見的Utility定義(一般經濟學定義)，只能找出以下兩個較為不同的定義，說明較為詳細的是Philip Jacobs & John Rapoport書中所提及的定義，其utility定義共有三個 (附有citation)，若此定義仍無法適切說明utility的話，可能得重新討論定義之方向，或從特定理論著手。

1. Utility is an index of preferences that can most easily be understood as a measure of satisfaction. Utility represents satisfaction or the level of welfare of an individual, measured in cardinal or ordinal utility term.

(The Economics of Health and Health Care 4th Ed, Sherman Folland, Allen C. Goodman, Miron Stano,2004, New York: Pearson Prentice Hall)

2. Utility:
(1) An index comparing various levels of an individuals’ satisfaction with alternative quantities of specified goods, services, or situations under certainty. The index that allows the quantification of differences between the levels us called cardinal utility
(Reference: Pigou, 1960, The Economics of welfare. London: Macmillan).

(2) A ranking of alternative bundles of goods and services under certainty, on the basis of better, equal, or worse, with no indication as to degrees of satisfaction (Ordinal utility).

(3) A ranking of alternative risky situations on the basis of an individual’s own preferences regarding probabilities (von Neumann-Morgenstern utility).
(Reference:Torrance et al, 1995, Multi-attribute preference functions, Pharmaco-Economics, 7:503-520.)

From book：The Economics of Health and Medical Care 5th Ed, Philip Jacobs & John Rapoport, Maryland:Aspen.