Paraphrasing the NY Times article by Pat Cohen:

… (Gravity Payments CEO Dan Price) surprised his 120-person staff today by announcing that he planned over the next three years to raise the salary of even the lowest-paid clerk, customer service representative and salesman to a minimum of $70,000.

The happiness research behind Mr. Price’s announcement on Monday came from Angus Deaton and Daniel Kahneman, a Nobel Prize-winning psychologist. They found that what they called emotional well-being — defined as “the emotional quality of an individual’s everyday experience, the frequency and intensity of experiences of joy, stress, sadness, anger, and affection that make one’s life pleasant or unpleasant” — rises with income, but only to a point. And that point turns out to be about $75,000 a year.