ABSTRACT

Traditional “head count” measures of poverty at advanced older ages understate the risk of falling into poverty because of survivorship bias due to the income-mortality gradient, which indicates that people in poverty have higher mortality rates than people with higher income. Survivorship bias is a form of sample selection bias. This paper presents a supplementary measure for poverty at older ages, based on an adaption of a model for correcting survivorship bias in rate of return data for mutual funds. Using U.S. longitudinal data from the Health and Retirement Study (HRS) for 1996 and 2002–2012 for the same cohort, we develop a new estimate of poverty at older ages that suggests that traditional cross-sectional measures understate the risk of falling into poverty by roughly a quarter. This finding has important implications for social programs that relate to the causes and consequences of the selectivity bias.

摘要

传统的高龄贫困“人数”衡量标准低估了由于收入-死亡率梯度导致的幸存者偏差而陷入贫困的风险，这表明贫困人口的死亡率高于收入较高的人。幸存者偏差是样本选择偏差的一种形式。本文基于对共同基金回报率数据中幸存者偏差校正模型的调整，提出了一种针对老年人贫困的补充措施。使用来自美国健康与退休研究 (HRS) 的 1996 年和 2002-2012 年同一队列的纵向数据，我们对老年贫困进行了新的估计，表明传统的横断面测量低估了陷入贫困的风险大约四分之一。