By Martin Shankleman
Employment correspondent, BBC News
Comparing salaries with Bill Gates may make you less happy
People who compare their earnings with others are damaging their health, according to new research to be presented at the annual conference of the Royal Economic Society this week.
They become less happy, more depressed, and less satisfied with life overall, the research says.
The authors, Professors Andrew Clark and Claudia Senik from the Paris School of Economics, claim human beings are constantly judging where they stand in relation to others, and one of the most pervasive comparisons is income.
They say three-quarters of people in the UK and the rest of Europe admit it is important to rank how much they earn against others, the typical comparison being with colleagues at work.
But the researchers conclude the more people compare their earnings with others, the less happy they become, as measured by answers to questions such as: Do you live comfortably? Do you feel optimistic? Have you been depressed in the last week? How satisfied are you with how life has turned out so far?
The researchers also found the amount of dissatisfaction people feel about their earnings, varied according to whom they compared themselves with.
The least damaging comparison is against colleagues, which may be because people hope one day to earn the same as their better-paid co-workers.
But the comparisons become more painful when the income is matched against family members; and the most toxic of all is against friends, which produce twice the hurt of comparisons with colleagues.
Middle-aged people are also more likely to brood about their income than young people. However, men and women are equally likely to suffer income envy.
The study also found that the more people dwell on income comparisons, the more they are in favour of state intervention to redistribute income from the rich to the less well-off.
The authors conclude that their research has practical lessons for how we lead our lives.
"Man may well be a social animal, but constantly looking over one's shoulder seems to make the world a less happy, more unequal place," they write.
The findings were of no surprise to one business psychologist, who remembers treating a young woman working in the City who was upset that she was "only" earning £100,000 a year.
"She wasn't long out of college and was extremely dissatisfied because she was on less than her colleagues," said the psychologist, who wished to remain anonymous.
"We've had this obsession with money, rather than people judging their work by how much they enjoy it. Pay is not a very important ingredient in enjoying your job," he added.
The research was based on analysing responses from 34,000 people in 23 countries who took part in the European Social Survey, carried out in 2006 and 2007.