Get Some Sleep, and Wake Up the G.D.P.

January is always a good month for behavioral economics: Few things illustrate self-control as vividly as New Year’s resolutions. February is even better, though, because it lets us study why so many of those resolutions are broken.

But a more important question may involve a resolution that so many of us fail to make. It involves a commodity that nearly everybody needs more of, and our failure to address it arguably has as much impact on our well-being as inadequate exercise and unhealthy eating.

The problem is very simple: Many of us need more sleep.

Here’s an alarming statistic: A survey by the Centers for Disease Control and Prevention found that one in 25 people admitted to having fallen asleep while driving during the previous month. To put that in perspective, mathematical models based on this data imply that an estimated 15 to 33 percent of all fatal crashes in the United States might involve a drowsy driver. But even that may be an underestimate, as some people who fall asleep at the wheel may be sheepish about acknowledging as much in a survey.

What does sleep have to do with economics? Doesn’t it sit squarely in the realm of physiology?

First, the economic consequences of inadequate sleep are surely huge. There may be more sleepy workers than drivers. In one month in 2008, a poll showed that 29 percent of workers had fallen asleep or had been very sleepy at work. The effects can add up: one study in Australia calculated the cost of sleeplessness at 0.8 percent of the country’s gross domestic product.

Yet even that number, which emphasizes the physical and medical consequences of inadequate sleep, omits the biggest potential impact on the G.D.P. Most of today’s workers rely on their mental and social skills. And if those workers don’t get enough sleep, their lethargy, crankiness and poor decision-making will hurt the economy in assorted and significant ways.

For example, one study has shown that “cyberloafing” — wasting time on the web — increases on the day after the start of daylight saving time, when people are short an hour of sleep. Other research shows how cognitive performance deteriorates when sleep is inadequate: We have less capacity to remember, to learn or to be creative, and we become less optimistic and less sociable. And these consequences aren’t reserved for extreme sleep loss: Studies show that two weeks of sleeping only six hours a night can have the same impact as one or two nights of total sleep deprivation.

There is an odd divide here. Ask why one person had an unproductive day at work, and lack of sleep often seems an obvious answer. But ask why national productivity has fallen, and reduced sleep can appear to be a frivolous answer. Yet what is total output but the sum of all individuals’ work?

Sleep deserves serious study by behavioral economists for another important reason. Some struggle with medical issues — like insomnia — that make sleep hard. But for many of us, the quantity and quality of sleep come down to a matter of choice. Still, only a few enterprising economists have looked closely at this, and generally those have assumed that we choose our hours of sleep optimally. The idea is that we thoughtfully trade the use of an hour of sleep for an hour spent doing something else. But it is worth questioning the assumption that these are rational and optimal choices. Judge for yourself. Was watching that extra episode of “Game of Thrones” last night worth the sluggishness you’re feeling right now?

We also need to ask another question: Why do we neglect our sleep? It’s not as if the ill effects of fatigue are a surprise. If for no reason other than self-interest, we are vigilant about our children’s sleep, so it’s hard to understand why we are so cavalier about our own. This puzzle is even more pointed because the benefits of sleep are immediate. Eat better or work out more, and you’ll see the benefits weeks, months or years down the road. Sleep more and you’ll see the benefits tomorrow.

The research on this question is sparse, so we must speculate.

Part of the problem may stem from a misunderstanding of physiology. We may overestimate our ability to overcome the effects of sleep deprivation. Have you ever told yourself, “I’ll be tired but I’ll just tough it out”? It’s easy to think that willpower will make us alert. Or we may believe that caffeine compensates for lost sleep. While it can make us more alert, as shown in a study on Navy SEALs, it does not restore all mental function. And it makes sleeping well even harder.

The problem is aggravated by a common belief that lost sleep can be made up for, that we can manage our “sleep debt.” But why should we be any better with this debt than we are with money? When the time comes for a payback, there always seems to be something more appealing for our money or time.

Whatever the reasons, the problem appears to be spreading. One careful study found that the number of “short sleepers” — those who got fewer than six hours of sleep a night — rose 22 percent from 1975 to 2006, a trend that was most pronounced and significant among full-time workers.

Technology is an obvious culprit here. Web searching and cellphone use both flourish in the wee hours. Before the dawn of the web, I would stay up watching television. But there is something soporific about television: I would often nod off. Not so when I’m online. As technologies expand, these problems may only worsen.

We can do something about this in our own lives. It’s not too late to add a resolution for this still-young year: to partake more in what Shakespeare called the “chief nourisher in life’s feast.” A good night’s sleep has immediate effects on our productivity, and, best of all, it can even help us keep our other resolutions.

Source: New York Times: Get Some Sleep, and Wake Up the G.D.P.