This paper studies the effect of income (wealth) inequality on interpersonal trust. We propose a theoretical framework that links trust, trustworthiness and inequality. The key feature is that agents do not necessarily observe the entire income distribution but base their assessment on reference groups (i.e. they might hold a biased view of reality). In this framework the negative impact of inequality on interpersonal trust is related to the individual-specific perception of inequality. This has important implications for the empirical analyses since researchers typically do not observe perceptions but only objective measures of inequality (e.g. the Gini coefficient). We show that the use of the latter is appropriate only under restrictive assumptions and in general will result in an underestimation of the true effect. An unbiased estimate of the effect of inequality on trust can be obtained with a measure of individual-specific perceptions of inequality. Survey data support our framework. Perceptions of higher inequality exert a strong negative effect on trust.

本文研究收入（财富）不平等对人际信任的影响。我们提出了一个将信任、可信度和不平等联系起来的理论框架。关键特征是代理人不一定要观察整个收入分配，而是根据参考群体进行评估（即他们可能对现实持有有偏见的看法）。在这个框架中，不平等对人际信任的负面影响与个体对不平等的感知有关。这对实证分析具有重要意义，因为研究人员通常不观察感知，而只观察不平等的客观衡量标准（例如基尼系数）。我们表明，后者的使用仅在限制性假设下是合适的，并且通常会导致对真实效果的低估。可以通过衡量个人对不平等的具体看法来获得不平等对信任影响的无偏估计。调查数据支持我们的框架。对更高不平等的看法对信任产生了强烈的负面影响。