Inequality and Mortality: Long-Run Evidence from a Panel of Countries

We investigate whether changes in economic inequality affect mortality in rich countries. To answer this question we use a new source of data on income inequality: tax data on the share of pretax income going to the richest 10 percent of the population in Australia, Canada, France, Germany, Ireland, the Netherlands, New Zealand, Spain, Sweden, Switzerland, the UK, and the US between 1903 and 2003. Although this measure is not a good proxy for inequality within the bottom half of the income distribution, it is a good proxy for changes in the top half of the distribution and for the Gini coefficient. In the absence of country and year fixed effects, the income share of the top decile is negatively related to life expectancy and positively related to infant mortality. However, in our preferred fixed-effects specification these relationships are weak, statistically insignificant, and likely to change their sign. Nor do our data suggest that changes in the income share of the richest 10 percent affect homicide or suicide rates.

本研究旨在探究富裕国家中，经济不平等的变化是否会对死亡率产生影响。为此，我们采用了一套全新的收入不平等数据来源：1903年至2003年间，涵盖澳大利亚、加拿大、法国、德国、爱尔兰、荷兰、新西兰、西班牙、瑞典、瑞士、英国及美国最富有的10%人口所获得的税前收入占比的税收统计数据。尽管该指标无法很好地表征收入分布下半部分群体的不平等状况，但它能够较好地反映收入分布上半部分的变化情况，同时也可作为基尼系数（Gini coefficient）的有效替代指标。在未纳入国家和年度固定效应（fixed effects）的情况下，前十分位群体的收入占比与预期寿命呈负相关，与婴儿死亡率呈正相关。然而，在我们优选的固定效应设定中，这些关联十分微弱，不具备统计学显著性，甚至可能出现符号反转。我们的数据也未表明，最富有的10%人口的收入占比变化会对凶杀率或自杀率产生影响。