Many politicians, journalists, and academics are obsessed with inequality. And they usually take it for granted that more equality equals more happiness. But does it? Jonathan Kelley and M.D.R. Evans of the University of Nevada took it upon themselves to investigate this question in a large-scale study published a few years ago. Their pool of data was remarkably extensive and included 169 representative surveys from 68 nations, in which a total of 211,578 people were surveyed.

On the one hand, the study drew on established questions from so-called “happiness research.” Respondents were presented, for example, with the item “All things considered, how satisfied are you with your life as a whole these days?” and asked to rate their satisfaction on a scale from 1 (dissatisfied) to 10 (satisfied). They were also asked: “Taking all things together, would you say you are: Very happy, quite happy, not very happy, not at all happy?”