The problem with any study like that is it's a) hard to actually measure happiness b) your wealth depends on everyone else's. If everyone else is making 10k/yea

The problem with any study like that is it's a) hard to actually measure happiness b) your wealth depends on everyone else's. If everyone else is making 10k/year, you're 75k feels comparatively like a lot more & goes a lot further because costs are scaled down similarly. More importantly, humans derive a lot of satisfaction generally from comparative analysis - if I'm doing better than my neighbor, I'm happy and if I think he's doing better I'm upset.