Relative deprivation and human flourishing: how do upward income comparisons affect health, happiness and life satisfaction?

Background: Relative deprivation induced by social comparisons is hypothesised to deleteriously affect health. Previous work has proposed the (CRi) over tilde index as a measure of relative deprivation; however, the performance of this novel index still needs further testing in the working-age population. This study examined the association of three relative deprivation measures (the Yitzhaki Index, income rank and the (CRi) over tilde index) with human flourishing outcomes. Methods: This cross-sectional study analysed data from 2177 working-age adults in Taiwan. We conducted least-squares linear models to investigate the association between relative deprivation measures and health, happiness, life satisfaction, meaning in life, social relationships, and subjective well-being. Results: When using sex and age as the reference group, for each increased SD in the Yitzhaki Index, the six human flourishing outcomes decreased by 0.10-0.20 SD. The results were consistent across various definitions of the reference group. Based on the Akaike information criterion, the Yitzhaki Index generally showed better model fits for health, happiness, life satisfaction and meaning in life, and had comparable model fits with the income rank for social relationships and subjective well-being. In comparing the relative performance of the (CRi) over tilde index, positive a parameters (0<alpha<1) generally showed better model fits, suggesting that individuals were more sensitive to comparisons with those more distant from their own income level. Conclusion: Policies to reduce relative deprivation by lowering income inequality could contribute to a higher level of health, happiness, life satisfaction, meaning in life, social relationships and subjective well-being.