In their recent study published in the Journal of Personality and Social Psychology (http://dx.doi.org/10.1037/pspp0000059), “Income Inequality Is Associated with Stronger Social Comparison Effects: The Effect of Relative Income on Life Satisfaction,” Felix Cheung and Richard E. Lucas find that “people were more strongly influenced by the income of their neighbors when income inequality was high.”
Cheung and Lucas’ study follows up on a 1998 study reporting that folks have greater life satisfaction when those around them make considerably less than when they make twice as much, or more.
Not only does economic inequality effect material conditions but it also informs self-perception and satisfaction with life. Both the 1998 and the 2015 studies note that to be poor when others around us are not can lead to psychological distress. As well, according to Cheung and Lucas, the disparity itself prompts comparisons.