US researchers have found that happiness can be yours for an income of $75k a year (or £48,814.44 as of this morning), although trousering more than that won't necessarily increase your joie de vivre.
Professor Angus Deaton, an economist at the Center for Health and Wellbeing at Princeton University, and Nobel Prize winning psychologist Professor Daniel Kahneman looked at surveys of 450,000 Americans carried out in 2008 and 2009 for the Gallup-Healthways Well-Being Index, which quizzed respondents on their day-to-day happiness and overall life satisfaction.
They found that people's happiness increased steadily as income rose to $75,000, but then levelled out. Their sense of success or well-being did, though, continue to rise beyond that figure.
Deaton said: "Giving people more income beyond 75K is not going to do much for their daily mood ... but it is going to make them feel they have a better life."
The two profs elaborated: "Perhaps $75,000 is a threshold beyond which further increases in income no longer improve individuals' ability to do what matters most to their emotional wellbeing such as spending time with people they like, avoiding pain and disease and enjoying leisure."
They added: "What the data suggest is that above a certain level of stable income, individuals' emotional wellbeing is constrained by other factors in their temperament and life circumstances."
Unsuprisingly, those earning less than the optimum $75k may find their emotional wellbeing seriously constrained by their life circumstances. As salary dropped, the researchers found "declining happiness and increased sadness and stress".
Deaton summarised: "Stuff is so in your face it's hard to be happy. It interferes with your enjoyment."
Deaton and Kahneman's study will appear this week in the Proceedings of the National Academy of Sciences. ®
According to Deaton, average US household income in 2008 was roughly $71,500, while "the median - or the point at which half of incomes are higher and half are lower - was $52,000". He explained that "the average skews higher than the median because of a few very high incomes".