Power naps can boost productivity by more than two per cent, while poor sleep costs firms two weeks productivity each year.
Just outside Valencia lies a small Spanish town called Ador where the siesta remains sacrosanct.
In 2015, the town’s mayor passed a law forcing all businesses to close between 2pm-5pm, banning ball games, and generally keeping noise to a minimum.
Ador is an anomaly. Elsewhere, the traditional afternoon nap has become an anachronism that is as foreign to most Spaniards as it is to tourists. Yet this sleepy Spanish town may be onto something.
Sleep science has progressed rapidly in recent years, with lab experiments confirming what many already suspected – that insufficient sleep can adversely affect cognitive function and mental health.
Bosses would do well to heed the warning. Wellbeing at work has become big business and can be the difference between skilled candidates choosing one organisation over another.
A recent report by the consultants Oliver Wyman found that 28 per cent of Generation Z workers – those born after 1997 – seek out benefits that help them cope with stress. That includes massage chairs, meditation rooms, and sleep pods in the office.
Yet the idea of ‘sleeping on the job’ remains anathema and only a few companies have begun building naps into the working day.
Clearly, more evidence is required before employers are willing to change the habits of a lifetime. That is exactly what we set out to provide with our study.
Traditionally, researchers have confined their work within two key parameters, exploring how night-time sleep impacts individuals in developed economies. Very little research has examined how sleep deprivation affects those in low-wage countries or the impact of short, day-time naps.
Established research has almost exclusively taken place in sleep labs, rather than looking at experiences in people’s day-to-day environments.
Are naps more beneficial that better night-time sleep?
To address that, we looked at a group of about 450 adults in Chennai, India. We used actigraphs, devices that measure sleep-wake cycles, to measure their sleep at home.
We found that low-income workers spent eight hours in bed, but slept for just 5.5 hours per night. The sleep they did have was poor quality and extremely interrupted, which was comparable to those in high-income countries with disorders such as sleep apnoea or insomnia.
In order to understand the relationship between sleep and real workplace outcomes, we invited these individuals to work for three weeks in an office environment that focused on data-entry work. Over these three weeks, we offered a series of interventions to the workers to test the relationship between their sleep and cognition, productivity and labour supply, decision-making, and wellbeing.
We were particularly interested in whether improving sleep beyond the poor levels at baseline would improve day-to-day outcomes in the workplace.
To test this, some participants were given sleep masks, fans, or mattresses to improve their environment, as well as advice on the benefits of good quality sleep and better sleep hygiene.
Some were additionally offered financial incentives and promised payment for extra sleep that was tracked on actigraphs. Finally, one group of employees was offered a 30 minute afternoon nap in a comfortable and quiet environment.
Our night-time interventions increased the length of sleep by 27 minutes. However, the extra rest did not improve workers’ cognition, productivity, decision-making or wellbeing. It also led to a slight reduction in labour supply, as people came into the office later because they were asleep for longer.
In contrast, employees in the nap trial saw improvements across all of those outcomes, despite reducing the time they were available to work.
This could be because naps were timed to coincide with a mid-afternoon circadian dip in energy, or because the environment we created for the naps supported higher-quality sleep than workers were used to having at home, where they had reported interruptions such as traffic noise or mosquitos.
Those who slept for longer at night did experience better physical wellbeing and task cognition than they had previously, but less so than those having afternoon naps. Mental health and attention levels also improved among the nappers, while they declined for those in the night-time group.
How much do naps power up productivity?
How can we quantify these improvements? We worked out that, on average, participants who enjoyed a ‘power nap’ were 2.3 per cent more productive over the course of the day.
As part of the experiment, we also randomly varied the pay rate that workers faced. During some periods, workers were paid four times more than during other periods.
Doing this only increased productivity by 14 per cent, which suggests that that allowing participants to take a midday nap increased their productivity by as much as a 50 per cent wage increase would.
More research would be beneficial, both for workers in low-income economies and for employers in the developed world. We also need more examples of how corporations can support employees to build naps into their working day.
However, the widespread lack of sleep adds an element of risk to the bottom line. A cross-country analysis by research organisation RAND Corporation in 2018 found that at a national level, up to three per cent of Gross Domestic Product (GDP) is lost due to lack of sleep.
The financial cost adds up just as quickly at an organisation level. A 2014 survey by the National Sleep Foundation in the US found that poor sleep caused between 23-45 per cent of the population to lose more than two weeks of working productivity every year.
Those stark figures have prompted some of the world’s biggest firms into action. Nike has reportedly created rooms where staff can sleep or meditate at its headquarters in Portland, Oregon. Meanwhile, Proctor and Gamble has lighting systems in its offices that regulate the sleep hormone melatonin, making it easier for employees to switch off when they finish work in the evening.
It is entirely possible for companies to carry out their own, informal experiments with employees into the value of naps. Perhaps identify two groups of employees and allow one set to take a nap, then compare the results over time, collating data where possible.
This does not require sophisticated technology. Simply track whether either group enjoys better outcomes than the other, to decide whether naps are worthwhile.
Introducing a small number of soundproof sleep spaces, or ‘pods’ could show a positive impact on employee productivity or wellbeing at a relatively low cost.
Educating employees on the value of high-quality sleep and encouraging them to carve out time in their daily schedule for a nap – especially when working from home – could also pay off.
It may seem counterintuitive to reduce somebody’s time working during the day, particularly at a time when budgets are squeezed and the cost of living is rising. But in the long term, the benefits could boost retention and engagement with the organisation.
In future, we could see more companies embracing a siesta and reaping the benefits of happier, healthier, more productive employees. Those firms that are caught napping are likely to miss out.
Bessone, P., Rao, G., Schilbach, F., Schofield, H. and Toma, M. (2021) The economic consequences of increasing sleep among the urban poor, The Quarterly Journal of Economics, 136, 3, 1887-1941.
Rao, G., Redline, S., Schilbach, F., Schofield, H. and Toma, M. (2021) Informing sleep policy through field experiments, Science, 374, 6567, 530-533.
Mattie Toma is an Assistant Professor of Behavioural Science, teaching The Economics of Wellbeing on the WBS undergraduate programmes and The Fundamentals of Economic Behaviour on the MSc International Business, MSc Business with Marketing, and MSc Business with Operations Management.
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