W. Henry Chiu

Skewness Preference, Risk Aversion, and the Precedence Relations on Stochastic Changes

This paper provides a general choice-theoretic characterization of the trade-off between risk and skewness, whose importance in understanding risk-taking behavior is well documented in empirical studies. The condition under which the prudence measure (Kimball 1990) characterizes the strength of an individuals downside-risk aversion against his own risk aversion is identified and interpreted in a unifying framework based on the concept of one stochastic dominant change preceding another and that of the desirability of a stochastic change. The framework is also shown to be useful for a better understanding of the Arrow-Pratt measure, the stronger Ross measure, and the coincidence of the characterizations of downside-risk aversion and prudence, as well as the relationship between stochastic dominances of different degrees.

Intersecting Lorenz Curves, the Degree of Downside Inequality Aversion, and Tax Reforms

This paper clarifies the conceptual distinction of downside inequality aversion (or transfer sensitivity) as a normative criterion for judging income distributions from the Pigou-Dalton principle of transfers. We show that when the Lorenz curves of two income distributions intersect, how the change from one distribution to the other is judged by an inequality index exhibiting downside inequality aversion often depends on the relative strengths of its downside inequality aversion and inequality aversion. For additive inequality indices or their monotonic transformations, a measure characterizing the strength of an index’s downside inequality aversion against its inequality aversion is shown to determine the ranking by the index of two distributions whose Lorenz curves cross once. The precise condition under which the same result generalizes to the case of multiple-crossing Lorenz curves is also identified. The results are particularly useful in understanding the distributional impact of tax reforms.

Risk Aversion with State-Dependent Preferences in the Rank-Dependent Expected Utility Theory

We extend the analysis of risk aversion with state-dependent preferences to the rank-dependent expected utility theory. We find that in this extended theory, for two preference relations to be comparable in risk aversion not only do their reference sets need to coincide (a condition first introduced by Karni [1983, 1985] in the original expected utility framework), but they must also rank the prospective state-dependent outcomes in the same manner. We formalize this additional condition by introducing the concept of certainty sets. Under our condition of comparability, various results and characterizations of interpersonal comparison of risk aversion are obtained. The implications for a specific insurance problem are also discussed.