…happiness inequality, that is.

According to researchers from the University of Pennsylvania,

As with previous analyses, we find that, on average, happiness has failed to grow since the 1970s. But beneath this average, we document some important striking differences across groups: Two-thirds of the black-white happiness gap has been eroded, and the gender happiness gap has disappeared entirely, with more recent data suggesting that it may even have inverted. Paralleling changes in the income distribution, differences in happiness by education have widened substantially.

Our more striking finding is the substantial decrease in happiness inequality through our sample.

The researchers did not attempt to determine why there has been a decrease in happiness inequality. Perhaps it has something to do with global warming.