It is said that money cannot buy happiness, but according to scientists, it depends what you spend it on.
New research suggests that using money to buy more free time - such as paying for a cleaner or cook to take the daily chores off your hands - does actually improve well-being.
In contrast, spending money on possessions does little to improve happiness.
"People who hire a housecleaner or pay the kid next door to mow the lawn might feel like they're being lazy," said study lead author Dr Ashley Whillans, assistant professor at Harvard Business School who carried out the research.
"But our results suggest that buying time has similar benefits for happiness as having more money."
The researchers surveyed more than 6,000 adults in the United States, Denmark, Canada and the Netherlands.
Respondents were asked if and how much they spent each month to buy themselves free time. They also rated their life satisfaction, and answered questions about feelings of time stress.
Those who spent money on time saving purchases reported greater 23 per cent greater life satisfaction. The effect held up even after controlling for income, although lowered to 15 per cent happiness boost as people had less money to spend on buying back time.
"The benefits of buying time aren't just for wealthy people," said psychology professor and the study's senior author Elizabeth Dunn, of the University of British Columbia.
"We thought the effects might only hold up for people with quite a bit of disposable income, but to our surprise, we found the same effects across the income spectrum."
To test whether buying time actually causes greater happiness, the researchers also conducted a field experiment.
Sixty adults were randomly assigned to spend £30 on a time saving purchase on one weekend, and £30 on a material purchase on another weekend. The results showed that people felt happier when they spent money on a time saving purchase than on a material purchase.
Despite the benefits, the researchers were surprised to discover how few people choose to spend their money on time saving purchases in daily life.
In a separate sample of 850 millionaires who were surveyed, almost half reported spending no money outsourcing disliked tasks.
A survey of 98 working adults asking how they would spend a windfall of £30 also revealed that only two per cent would use it in a way that saved them time.
"Although buying time can serve as a buffer against the time pressures of daily life, few people are doing it even when they can afford it," added Prof Dunn.
"Lots of research has shown that people benefit from buying their way into pleasant experiences, but our research suggests people should also consider buying their way out of unpleasant experiences."
The research was published in the journal Proceedings of the National Academy of Sciences.