n. The tendency for a person's economic expectations and desires to rise at the same rate as his or her income, resulting in no net gain of satisfaction or happiness.
Looking at the data from all over the world, it is clear that, instead of getting happier as they become better off, people get stuck on a "hedonic treadmill": their expectations rise at the same pace as their incomes and the happiness they seek remains constantly just out of reach.
Studies show that happiness rises with incomes — up to the point at which basic needs are met, after which it stagnates as aspirations also rise with income. The recent Nobel Prize-winning economist and psychologist Daniel Kahneman calls this a "hedonic treadmill." Like the proverbial rats, we run faster and faster — and so do our aspirations — but the bottom line is the old cliche: Money can't buy happiness.
One of the most surprising conclusions is the extreme difficulty of remaining happy, or unhappy, for any length of time. People rendered paraplegic or quadriplegic were compared in one study with pools winners. Within a year, both registered similar levels of happiness, although there was a slight bias in favour of the able-bodied pools winners. This strongly supports Eysenck's theory of a "hedonic treadmill". "The trouble is, if nice things happen to you, your expectations go up." With no escape from the hedonic treadmill, reducing expectations becomes the key to happiness.