I assume you're referring to: http://www.pnas.org/content/107/38/16489.abstract

for the $80k number.

In case you haven't seen it, there's another paper that argues the opposite: more money does make you happier (but only if you know how to use it). http://scholar.harvard.edu/files/danielgilbert/files/if-mone...

I make more than $80k and I can certainly say that I was less stressed before I took a huge pay cut. On the other hand, I like my job more so I guess I might actually still be happier. All else being equal though, if I made more I imagine I would be much less stressed..