The study's authors surveyed 6,000 individuals at diverse income levels in multiple countries, including the United States, Canada, the Netherlands, and Denmark. The survey asked participants about whether they spent money monthly to hire others to take care of unpleasant or time-consuming daily tasks or chores — such as cleaning, yard work, cooking, and errand-running — and if so, how much they spent. Respondents were also asked to rate their "satisfaction with life" and report demographic information, such as their income level and whether they were married and had children.
Across all studies, those who spent money to outsource disliked tasks and/or save time had a stronger life satisfaction rating. Findings were consistent across income spectrums.
Of course, correlation does not necessarily indicate causation, so the researchers designed a follow-up experiment to further test their hypothesis.