I read various claims, but this HowStuffWorks article seems the most representative (bolding is all mine):
The one place that money and happiness are significantly linked is when a person is unable to afford to meet their basic needs. There is an appreciable difference in levels of happiness between those below the poverty level and those above it...
Once people pass that poverty threshold, though, the money boost tapers off; Inuits in Greenland and Masai ranchers living in Kenyan dung huts are just as happy as the high-society Americans.
From Psychology Today:
...disappeared. Once people reached this level of income, sufficient to meet basic needs (except if you happen to live in Marin county, like I do), more income did not make people any happier or less stressed. Rather, individual personality factors and life circumstances were the major factors determining happiness.
I understand these are statistics. But these articles are also prescriptive to the individual reader,
For starters, you may want to rethink quitting that job of yours...People with jobs they find highly satisfying but that don't pay as well can be just as content.
people also tend to report higher levels of satisfaction after spending money on experiences rather than things
research tells us are the real sources of happiness -- social connections, challenging work, good health
Research studies show that spending money on experiences, such as family vacations, educational courses, or psychotherapy provides more happiness “bang for the buck” than spending money on possessions.
Is there a global absolute threshold above which earning more doesn't make you happier?
Can this statistical research be used to advise me on how to choose life priorities?
Should I rather spend on a movie ticket than a T-shirt (it's a valid trade-off where I live, in case you felt it was absurd) since experiences are superior?