Happiness research has its critics. But so does inequality research. I am always stunned that most findings from the latter do not bother to look at inter-temporal mobility between strata -- especially in a country with substantial in-migration of very poor people.
What then to do with happiness inequality research? This NBER report (by Stevenson and Wolfers) is interesting because the authors report that the black-white happiness gap has shrunk while the male-female happiness gap has disappeared.
I guess that the case for happiness redistribution policies has subsided. Good thing. The incoming administration has its hands full.
Each year, I ask the standard question in class: If we could (magically) double income, thereby eliminating almost all poverty but increasing inequality, would you favor the magic? Year after year, most say "no".
UPDATE
Perhaps, I spoke too soon. The possibilities are endless. There is also consumption, happiness and climate change.