Researchers found that life contentment only rose steadily with annual income up to level -- $75,000, or just below ￡50,000.

The quality of the randomly-selected participants' everyday experiences did not improve significantly beyond a salary of ￡48,960.98.

Earning less than that amount can make you miserable-but earning more does not greatly increase enjoyment of life, it was found.

Money can buy you happiness but only if you earn ￡50,000 a year-after that you really have to work for it, a study claims.

Once earnings soared above this the important things in life such as family and well-being made money much less significant.

But as income dropped from that amount, respondents reported decreasing happiness and increasing sadness and stress,

according to the findings published in Proceedings of the National Academy of Sciences.

The psychologists Prof Daniel Kahneman and Prof Angus Deaton explained people's life evaluations rise steadily with income but the quality of emotional daily experiences levels-off once earnings reach a certain amount.

"The question of whether 'money buys happiness' comes up frequently in discussions of subjective well-being in both scholarly debates and casual conversation."

Prof Kahneman and Prof Deaton, of Princeton University, New Jersey, said:

The researchers said the study does not imply people's lives will not improve after a raise in annual income from $100,000 to $150,000. But above a certain income people's emotional well-being is held back by other more important issues.

The data also suggested the emotional pain of unfortunate events or circumstances including disease, divorce and being alone are exacerbated by poverty.

"More money does not necessarily buy more happiness, but less money is associated with emotional pain."