Borda’s Rule and Arrow’s Independence Condition
指出阿罗的无关备选方案独立性条件过于严格，因为它排除了社会福利函数对个人偏好强度的敏感性。作者提出一个修正版本MIIA，并证明MIIA与其他公理共同唯一刻画了博尔达计数作为社会福利函数。
We argue that Arrow’s independence of irrelevant alternatives (IIA) condition is unjustifiably stringent because it rules out making a social welfare function sensitive to individuals’ preference intensities. Accordingly, we propose a modified version of IIA, MIIA, that is a necessary and sufficient relaxation of IIA for taking account of intensities. Rather than obtaining an impossibility result, we show that MIIA together with several other axioms (satisfied by virtually all voting rules and social welfare functions used in practice and studied in theory) uniquely characterizes the Borda count (sometimes called rank-order voting) as a social welfare function.