Status, the Distribution of Wealth, Private and Social Attitudes to Risk
假设个人不仅关心自身财富，还关心财富带来的相对地位，并研究这种地位关注对风险承担行为的影响。模型自然解释了弗里德曼-萨维奇提出的凹-凸-凹效用函数，并揭示了均衡财富分配可能产生中产阶级且存在帕累托低效等关键差异。
This paper supposes an individual cares about his/her own wealth not only directly but also via the relative standing that this wealth induces. The implications for risk-taking are investigated in particular. Such a model provides a natural explanation of the concave-convex-concave utility described by Friedman and Savage. However, there are a number of key differences between the present model and any model based on own wealth alone. For example, an equilibrium wealth distribution here may have a middle class. Further, the status interaction involves an externality and an equilibrium wealth distribution may be Pareto inefficient. but also about the implied relative standing in the distribution of wealth has a long but checkered history. (An early exponent of such ideas was, of course, Veblen (1899).) It is indeed a notion which most economists reject, albeit usually without explicit comment. (A notable and articulate exception, however, is Frank (1985), for example. See also the references Frank cites on pp. 33-34.) It is, however, a notion with substantial intuitive appeal and it seems useful to ascertain its consequences before coming to a final judgement as to its merits. The present paper is concerned with deriving the consequences of such valuation of status for risk taking. What seems to be the sharpest possible model is adopted here. This assumes that what is essentially ordinal rank in the wealth distribution enters von Neumann-Morgenstern utility as an argument in addi- tion to wealth itself. Thus higher wealth increases utility not only directly but also indirectly via higher status. In the interests of both simplicity and drama, it is typically assumed here that all individuals have identical utility functions which are concave in wealth but convex in status. Section 2 discusses how the model provides a natural explanation of the fundamental phenomenon addressed by Friedman and Savage (1948) that individuals may simultaneously purchase insurance and participate in lotteries. Although each individual here has a utility function which is concave in wealth itself, utility can nevertheless be convex in wealth over some range when the indirect effect via status is included. This effect is enhanced by the convexity of utility in status, but will follow in any case if increasing wealth entails moving up in status much more rapidly than losing wealth entails moving down. It is shown