[natenthe]

For someone to not understand this without a study, I think they would need to be oblivious to the state of the economy, the cost of living in the average metropolitan area where the average American lives, and social dynamics / cultural issues in America.

Also, if you've experienced significantly different levels of salary then this is obvious.

[klyrs]

"Money doesn't buy happiness" is also considered obvious common sense. The study is looking for the phase boundary where one obvious statement ceases to apply and the other takes over.

[reedf1]

I think you've missed the point of science somewhere.

[newbie2020]

Sometimes common sense lets us take shortcuts without having to wait for or spend on the science.