“The key to happiness”

I came across this line during a dialog earlier today:

‘research consistently shows that there is at least some correlation between having money and being satisfied with life.’

Can someone point me to that research? My experience and my observation in life has been that if you have enough money to meet your basic needs (food, shelter and clothing) then happiness depends on having enough money to meet your wants and desires. You have two choices - learn to make more money, or learn to want fewer things.”

(Daniel, The art of zen living)