An Economic Index of Riskiness
定义了一个赌博的风险性指数，即常数绝对风险厌恶者对该赌博无差异时的绝对风险厌恶的倒数，并通过公理刻画其性质，如次可加性和随机占优一致性。
Define the riskiness of a gamble as the reciprocal of the absolute risk aversion (ARA) of an individual with constant ARA who is indifferent between taking and not taking that gamble. We characterize this index by axioms, chief among them a “duality” axiom that, roughly speaking, asserts that less risk‐averse individuals accept riskier gambles. The index is positively homogeneous, continuous, and subadditive; respects first‐ and second‐order stochastic dominance; and for normally distributed gambles is half of variance/mean. Examples are calculated, additional properties are derived, and the index is compared with others.