We draw attention to an important, yet largely overlooked aspect of evaluating fairness for automated decision making systems---namely risk and welfare considerations. Our proposed family of measures corresponds to the long-established formulations of cardinal social welfare in economics. We come to this proposal by taking the perspective of a rational, risk-averse individual who is going to be subject to algorithmic decision making and is faced with the task of choosing between several algorithmic alternatives behind a Rawlsian veil of ignorance. The convex formulation of our measures allows us to integrate them as a constraint into any convex loss minimization pipeline. Our empirical analysis reveals interesting trade-offs between our proposal and (a) prediction accuracy, (b) group discrimination, and (c) Dwork et al.'s notion of individual fairness. Furthermore and perhaps most importantly, our work provides both theoretical and empirical evidence suggesting that a lower-bound on our measures often leads to bounded inequality in algorithmic outcomes; hence presenting the first computationally feasible mechanism for bounding individual-level (un)fairness.

本研究针对自动决策系统公平性评估中常被忽略的风险和福利考虑提出了一种基于福利的公平性度量方法，其凸形式允许我们将其作为任何凸损失优化流程的约束条件进行集成，并通过实证分析揭示了与预测准确性、群体歧视和个体公平性之间的有趣权衡关系。该方法是第一个能够限制个体不平等性的计算机可行机制。

无知之幕背后的公平性：自动决策的福利分析