Income is more protective against pain in more equal countries

It is empirically well-established that the rich suffer less pain on average than the poor. However, much less is known about the factors that moderate the size of the income gradient of pain. Using data from over 1 million adults from 127 countries worldwide, this article conducts a systematic test on whether income inequality moderates the pain gap between the rich and the poor. While pain is negatively associated with income in all but one country, there is strong evidence to suggest that an increase in income is much more protective against pain in countries where the income distribution is relatively more equal. The results are robust to using different measures of income inequality, removing outliers, and accounting for country and year fixed effects. We explain our results through the lens of income rank effects on health outcomes. Overall, our findings suggest that pain-reducing policies through income redistribution may need to take income inequality into consideration when evaluating their effectiveness.