From Subtle Being..

"On a scale of 1 to 7, where 1 means "not at all satisfied with my life" and 7 means "completely satisfied," the people on Forbes magazine's list of the 400 richest Americans average 5.8—the same as the Inuit people in Greenland and the cattle-herding Masai of Kenya, who live in dung huts with no electricity or running water. Calcutta's slum dwellers score only a little lower, at 4.6.

Psychologists Ed Diener and Martin E.P. Seligman analyzed more than 150 studies on wealth and happiness and found that "economic indicators have glaring shortcomings" when it comes to determining how happy people are. They report that, in many countries, "although economic output has risen steeply over the past decades, there has been no rise in life satisfaction…and there has been a substantial increase in depression and distrust…Economic success falls short as a measure of well-being, in part because materialism can negatively influence well-being, and also because it is possible to be happy without living a life of luxury."

Also, people who say they're happy usually go on, years later, to earn higher incomes than people who say they're not. We would think that being discontent would inspire people to succeed, but the opposite seems to be true."