By Timothy Revell.

A high-level conversation has gathered pace in recent years about how long we should be working. Advocates of shortening the standard eight-hour day have long argued that doing so could lead to happier, healthier and maybe even more productive lives.

Some research has cast doubt on the idea that fewer hours would make us better able to maintain productivity, but a newly-completed study has re-opened the case. If we are on the verge of another historic drop in hours, is that a good thing?  

History is full of fights over working hours. During the industrial revolution factory owners maximised profit by keeping plants open as long as possible, leading to Dickensian 60-hour working weeks.

But in the last century, hours gradually fell away as workers negotiated better terms of employment. By the turn of the millennium, hours were averaging around 40 a week, where they have pretty much plateaued since.

As long ago as the 1930s, the economist John Maynard Keynes was predicting that as living standards rose in rich countries, working hours would fall. We should expect a 15-hour week within a hundred years, he said.

The latest research is beginning to suggest that, under the right conditions, a shorter working week is the way forward. Is this the future?

That clearly hasn’t happened,despite proposals by respected organisations like the New Economics Foundation, a think-tank based in London. In 2010, it began advocating a gradual transition to a 21-hour working week.

Such a short week might not be a disaster for productivity, if history is our guide. Going from 60 to 40 hours a week had no ill-effects on productivity (whereas working more than ten hours a day does). By the most important measures, we are more productive today than at any time in history. The question is whether shortening the working week further will boost productivity even more. 

Ten years ago, the Swedish National Institute of Working Life tried to find out, using a randomised controlled trial involving more than 500 public-sector workers

For 18 months, half the group went from working eight hours a day to six, with a corresponding cut in workload – although they remained on full pay. The other half stuck with their normal eight-hour shifts.

To make sure that jealousy didn’t influence outcomes, whole workplaces were put into one or the other group. At the end of the trial, the people working shorter hours said they felt happier and less stressed. Productivity, however, was a different story: the researchers couldn’t find the evidence to reach a conclusion.

When most people worked in factories, it was much easier to quantify productivity in terms of, say, the number of cars made or the number of books bound. Measuring productivity in office-based or service-sector jobs is far less straightforward. 

“It’s almost impossible to get any useful data,” says Torbjörn Åkerstedt at the Stress Research Institute in Sweden, who was part of the team behind the study.

Sick leave reduced by 10%

So they had to look for other measurable benefits. Here the news is disappointing for fans of leisure time: reducing working hours had no discernible effect on empirical indicators of stress like levels of the hormone cortisol. And people were no less likely to take sick days. “That was pretty surprising,” Åkerstedt says.

So much for the idea that a six-hour day improves productivity or health. That Swedish study closed the case for a decade but, over the past couple of years, with renewed interest in the subject a few high‑profile trials have been looking again.

Last year, a trial in the northern Swedish town of Umeå came to the same conclusions, finding that sick leave increases when working hours are lowered. But these results were contradicted by a longer trial, one that followed medical staff at a retirement home in Gothenburg for two years. 

This time, researchers found that the six-hour working day reduced sick leave by 10%. This study also did a slightly better job of specifying measures of productivity and identified some improvements. 

“There was a big increase in the number of activities organised for patients,” says Daniel Bernmar, the councillor in charge of the care of elderly people in Gothenburg. The study gave insight into better measures of not only productivity but also satisfaction. “People came to work happier and did a better job,” says Bernmar.

This became especially salient when one company took up the six-hour working day on a trial basis last year.

A Tasmanian accounting and financial services firm has achieved record output and revenue since allowing staff to work five-hours a day on full salary. So what's the catch?

Agent Marketing, based in Liverpool, UK, thought everyone’s jobs would be improved by six-hour days and mandatory lunch breaks. But after two months, staff voted against keeping the new hours. The verdict: it was just too stressful. “Six hours just wasn’t enough time to get their work done,” says Jeanette Gill, one of the employees who took part in the trial.

But that didn’t mean they went back to the old system at the end of the trial. People did want more time off – they just wanted more control over it as well. Now, every employee finishes a couple of hours early on Fridays and on one other day of their choosing.

So the latest research is beginning to suggest that, under the right conditions, a shorter working week is the way forward. Is this the future? Maybe, but the potential for implementing it varies considerably. People at a marketing agency can feasibly go home a bit early one day, but you can’t just do the same at, say, a hospital that needs to be properly staffed around the clock.

Even where a six-hour working day is easily introduced, it might be little more than an illusion. Technology tempts us to be always-on, with smartphones instantly notifying us of work emails and even letting us access remote desktops.

There have been nascent efforts to rein in this virtual overwork. This year, employees in France gained the right to disconnect, to completely ignore their smartphones outside office hours. 

The perils of working too much

The jury is still out on whether reducing working hours leads to health benefits, but in the other direction the case is long settled. As employees labour beyond 50 hours a week, the risk of coronary heart disease and stroke goes up.

One meta-analysis of studies covering more than half a million people in total found that those who work 55 hours a week are 13% more likely to develop coronary heart disease and 33% more likely to have a stroke, compared with those working between 35 and 40 hours.  

“There is also some evidence of a link between long working hours and poor mental health, although these studies are not as conclusive as those related to heart disease and stroke,” says Mikko Härmä at the Finnish Institute of Occupational Health.

We know what happens when people are pushed to the limit. In Japan, karoshi – death by overwork – is at an all-time high, with 1,456 cases last year. The term covers death by cardiovascular illness or stroke, as well as suicide. It is possible for family members to claim compensation, but only if their deceased relative has clocked up at least 160 hours overtime in one month, or 100 hours overtime for three successive months.

The robots are coming

But whether you like the idea of a six-hour day or not, soon you might have no choice. The reason is automation.

“Some people say that robotics and artificial intelligence will completely replace humans in the job market,” says Lesley Giles at the Lancaster University Management School, UK. A third of US business leaders and managers already feel that way, according to a survey published by the Pew Research Center. If AI doesn’t replace you, it is sure to reduce control over your employment, courtesy of the rise of the gig economy and companies like Uber and Taskrabbit.

For now, most people still prefer to work in more traditional types of employment, says Giles: jobs, not gigs. The next big fight in the world of work may not be for shorter hours, but the right to a stable job. Because although some have argued for replacing employment with universal basic income, the benefits of working go far beyond paying the bills.  

“If we think as a society that everyone should have a good job, we need to take steps to make that happen,” says Sarah Lyall at the New Economics Foundation.

Auditors and accountants are known for tending to work longer hours, especially when deadlines loom. So is this still the case today? Acuity investigates.