No Generalizable Effect of Income Inequality on Public Support for Redistribution among Rich Democracies, 1987-2010

We revisit a longstanding hypothesis that the public become more supportive of redistributive policy as income inequality rises. Previous tests of this hypothesis using various forms of general least squares regressions are inconclusive. We suggest improvements and alternatives to these tests. Using the World Inequality Data and International Social Survey Program we analyze 91 surveys in 19 countries. We incorporate three alternative measures of income inequality, including a measure of liberalization as a known cause of income inequality increases. We also employ two alternative test formats that arguably reflect the data generating model better than a least squares regression. The first is vector-autoregression aiming to account for path dependency of public opinion and income inequality, and the endogeneity between them. Next is qualitative comparative analysis to capture sets of conditions that collectively should have led to inequality having an impact on public opinion. Finally, we run our regression models separately for low and high socio-economic strata. In all tests we find no measurable impact of income inequality on support for redistribution. From a macro-perspective we argue that this suggests ruling out a general effect that exists across space and time, and focusing instead on theory to explain why there should not be a general effect. Some arguments suggest the public are normatively opposed to what sounds like ‘handouts’. We therefore discuss model specification via theory, but also Type II errors, statistical power and the limitations of our conclusions.

我们重新审视了一个长期存在的假设，即随着收入不平等的加剧，公众对再分配政策的支持度将逐渐提高。此前，该假设通过各种形式的广义最小二乘回归进行检验，但结果均未得出明确结论。我们提出了对现有检验的改进与替代方案。利用世界不平等数据和国际社会调查项目，我们对19个国家的91项调查进行了分析。我们引入了三种关于收入不平等的替代性度量指标，包括一项衡量自由化作为收入不平等加剧已知原因的指标。此外，我们还采用了两种替代性测试格式，这些格式或许能比最小二乘回归更准确地反映数据生成模型。第一种是向量自回归，旨在解释公众意见和收入不平等之间的路径依赖性以及它们之间的内生性。接下来是定性比较分析，旨在捕捉那些共同导致不平等对公众意见产生影响的条件集合。最后，我们将回归模型分别针对低社会经济阶层和高社会经济阶层进行运行。在所有测试中，我们没有发现收入不平等对再分配支持度的可测影响。从宏观视角来看，我们认为这表明排除了存在于时空跨度的普遍效应，转而聚焦于解释为何不应存在普遍效应的理论。一些论点表明，公众在规范性上反对看似‘施舍’的事物。因此，我们不仅通过理论讨论模型设定，还探讨了第二类错误、统计功效以及结论局限性的问题。