We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
Most of the studies he discusses avoid defining happiness, and just let people report. At issue, of course, is that as long as one is not in dire straits, happiness and contentment in life depend on non-economic factors: temperament and personality, relationships, family, hobbies and interests, etc.
There is no one "happiness." Some are most happy when taking risks, others more comfortable when they feel more secure. Material gain is not a universal goal.
indeed happiness cannot be defined by any one thing. For some people it may therefore require a larger amount of money to obtain the same degree of happiness as compared to others.
This is of course true even for people who have would be happy with the same life, if they live it in different places.
A small house, with some decent furniture, and 3 meals a day for example may mean you need to earn $10 a week in one place or $1000 in another depending on pricing and tax levels.
And that is what many would consider roughly a minimum level of worldly comforts needed to enjoy life.
Being retired and traveling to national parks and other remote and not so remote wilderness areas I often encounter young people who are "tramping" around the country or hiking one of the many major trails. They seem to have two consistent traits; they are happy and they are poor/broke. Often they are intelligent people and many have some college or finished college. They are broke by choice. It would be interesting to bale to meet and talk to these same people 20 years later and see what they have done with their lives and what choices they have made. It is after all, our choices that make us wealthy, and/or happy or poor and/or unhappy.