“Economists and psychologists have spent decades studying the relationship between wealth and happiness, and they have generally concluded that wealth increases human happiness when it lifts people out of abject poverty and into the middle class but that it does little to increase happiness thereafter. Americans who earn $50,000 per year are much happier than those who earn $10,000 per year, but Americans who earn $5 million per year are not much happier than those who earn $100,000 per year.”
–Daniel Gilbert. Stumbling on Happiness. New York: Vintage Books, 2006. Quote on page 217.