Do you lie awake at night worrying you’re not getting enough sleep? You’re not alone – some countries are in the middle of a sleeplessness epidemic which has the potential to damage people’s health and productivity.

Among the most rested countries surveyed by Sleep Cycle, an app that tracks how much shuteye people are getting, New Zealand comes top with the average Kiwi clocking up in excess of 7.5 hours per night.

Who's sleeping easy? Image: Matt McLean / Sleep Cycle / IMF / The Economist

Finland, the Netherlands, Australia, the UK and Belgium all rank highly for sleep, too, with Ireland close behind.

But not all developed economies rest well; South Korea and Japan are the world’s worst countries when it comes to getting a good night’s sleep. The problem of sleeplessness in Japan is well-documented, particularly in relation to the phenomenon of karoshi – death caused by lack of sleep.

Sleepwalking into trouble

Thankfully, cases of karoshi are relatively rare. But long before a person’s health and wellbeing are critically endangered, sleep deprivation will eat away at their ability to do their job.

The cumulative effect of compromised productivity adds up to the equivalent of a slew of working days being lost. According to Rand Corporation, the US loses the equivalent of around 1.2 million working days per year due to people not getting enough sleep. In Japan, around 600,000 working days are lost per year, while in the UK and Germany it stands at around 200,000.

All these lost days have an unavoidable effect on a country’s economic output. The US loses approximately $411 billion a year, or 2.28% of its GDP. For Japan, that’s around $138 billion a year (2.92% of GDP). In Germany, it equates to $60 billion (1.56% of GDP) and in the UK it’s $50 billion (1.86% of GDP).

To sleep, perchance to dream

The fact that small improvements in sleep can be amplified into much larger economic gains is something of a wake-up call.

If everyone in the US who sleeps fewer than six hours a night got between six and seven hours, there would be a $226.4 billion boost to the economy. All that from what is, effectively, less than an extra hour in the land of nod each night.

This level of improvement could add around $75.7 billion to the Japanese economy, a point that hasn’t been lost on the owner of a Tokyo-based wedding company called Crazy. Last year, the firm’s CEO, Kazuhiko Moriyama announced a cash-bonus for employees who were getting at least six hours sleep a night. “You have to protect workers’ rights, otherwise the country itself will weaken,” he said.

People in Saudi Arabia, the Philippines, Malaysia and Egypt are also some of those most likely to be sleep deprived. But while the average of 7.5 hours a night that New Zealanders enjoy each night is higher than anywhere else, even that might not be enough.