The Economics of Sleep, Part 2 (Ep. 212)

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Our latest Freakonomics Radio episode is “The Economics of Sleep, Part 2.” (You can subscribe to the podcast at iTunes or elsewhere, get the RSS feed, or listen via the media player above. You can also read the transcript, which includes credits for the music you’ll hear in the episode.)

Ph.D candidate Matthew Gibson found that the further west you live in a timezone, the less you make. (Photo: Jamie Mullins)

The economist Matthew Gibson found that people on the eastern edge of time zones make more money. (photo: Jamie Mullins)

In our previous episode, we primarily discussed the health implications of sleep. This time, we look at the economic impact. One big takeaway: if you sleep more, you will likely earn more money. How do we know this? Thanks to a fascinating paper by Matthew Gibson and Jeffrey Shrader, called “Time Use and Productivity: The Wage Returns to Sleep.” As Gibson tells us, economists have traditionally not paid too much attention to sleep — in part because good data were hard to come by:



GIBSON: What we really need is something like an experiment for sleep. Almost as though we go out in the United States and force people to sleep different amounts and then watch what the outcome is on their wages. And it turns out that ever since we’ve put time zones into place, we’ve basically been running just that sort of giant experiment on everyone in America.

So Gibson and Shrader looked at similar populations that lie at opposite ends of time zones — for instance, Huntsville, Alabama (on the eastern edge of the Central Time Zone), and Amarillo, Texas (on the western edge). Even though cities like this are on the same clock, the western city gets roughly an hour more of sunlight – which means that people there tend to go to bed later. But they have to wake up the same time as people in the eastern city – so, on average, they get less sleep. Gibson and Shrader could then look at the wage data in places like this to see how an extra dose of sleep affects earnings:

GIBSON: And we find that permanently increasing sleep by an hour per week for everybody in a city, increases the wages in that location by about 4.5%.

But there’s much more in this episode. Among the many voices you’ll hear:

+ Lauren Hale, a sleep researcher at Stony Brook University and a board member of the National Sleep Foundation. In last week’s episode, she told us she’d keep all computer screens out of her bedroom for a week and see how she slept. This week, she tells us the result.

+ Dan Hamermesh, a professor of economics at Royal Holloway University of London, emeritus professor at the University of Texas at Austin, and one of the first scholars to consider the economics of sleep:

HAMERMESH: Indeed, when this research was first written up in 1989, the headline was “Sleep, Why Bother? It Costs Too Much.” And the argument being there, that if you have other things to do with your time like make money, you’ll sleep less. The crucial point is sleep is not entirely biological, it responds to incentives. That’s the interesting economic point.

+ David Dinges, a professor of psychology and psychiatry at Penn, who tells us about his experimental research looking into the cumulative costs of sleep loss:

DINGES: The less sleep we gave people at night — so if went from seven or eight hours a night down to six or five — the more we got this cumulative rate of build-up of these deficits. They got worse every day. When the sleep got very short, down to four hours or three hours, they got worse every day very rapidly and very dramatically. So there was a dose-response function. The less sleep you got chronically, the more rapidly you deteriorated.

The economist Jens Bonke found that early birds to get paid more. (photo: Ernst Laursen)

The Danish economist Jens Bonke found that early birds make more money. (photo: Ernst Laursen)

+ Jens Bonke, an economist and senior researcher at the Rockwool Foundation in Copenhagen, whose research (gated) examines whether early birds really do get more worms. Short answer: yes!

Heather Schofield is doing experimental sleep research in India, where there are a lot of barriers to a good night’s sleep. (photo: Evgenia Eliseeva)

Heather Schofield is doing experimental sleep research in India, where there are a lot of barriers to a good night’s sleep.
(photo: Evgenia Eliseeva)

+ Heather Schofield, a postdoc fellow at the Center for Global Development, who is conducting experimental research (along with Frank Schillbach of MIT and Gautam Rao of Harvard) in India, where there are a lot of barriers to good sleep:


SCHOFIELD: Basically we’ll conduct a lottery and half the people in the study will be given things to help them sleep better at night. So we’ll give them a mat to sleep on, something like a camping mat, which makes the surface softer. We’ll give them a pillow so their neck isn’t as stiff. We’ll give them a light sheet and a fan to help keep the mosquitoes away. They’ll also get an eyeshade and ear-plugs to help deal with the light and the noise. In addition to that, we’ll also ask them to take a nap in the office every day. They have that choice whether or not they want to. But it will be a very pleasant environment where they can go where it’s cool and comfortable and take 20 or 30 minutes just to rest. Because there’s actually pretty good evidence just from work here in the U.S. and in other developed countries that short naps of 20 or 30 minutes can actually really improve your cognitive performance and your ability to kind of focus.

CEO of a health consultancy, Dan Pardi gives advice on how to get better sleep based on our individual metabolisms. (Photo: Christopher Kern)

Dan Pardi of Dan’s Plan has a lot of sleep advice. (photo: Christopher Kern)

+ Dan Pardi, CEO of the health consultancy Dan’s Plan, who has all kinds of advice about how we can all sleep a bit better, and in a style that suits our individual metabolisms.

What’s the Freakonomics prescription for a good night’s sleep? A good pair of earplugs and some Goldberg Variations, preferably played by Glenn Gould.



As is hinted at in this episode by the economist talking about the relative advantage of "morning people" over "night people", the way our society is structured is in many ways - ie work schedules, expectations about normal times of business, etc... not well structuredto meet our basic biological imperative such as sleep. The "food environment" too has gotten a lot of attention in this regard since in the US it encourages obesity. Really addressing widespread sleep deprivation, obesity and other issues that arise because of the disconnect between modern technology / society and our evolutionary history may take some fundamental changes in the way our society is run.

Ironically, it has been the economic profession and its emphasis on economic growth without regards to the cost of that growth and to the value of difficult-to-measure inputs to happiness (like the feeling of a good night's rest), that has been at least partly responsible for the mismatch here.


Dinilio Jiménez

Just finished hearing the episode and thought the tip at the end about wearing yellow glasses to filter blue light was interesting. I've read many studies on this and looked to see what other solutions people found. Turns out there is an app for that haha. I found an app(Bluelight Filter for Eye Care) that will filter the blue light from your phone's screen to reduce eye strain and the effect talked about at the end of the episode. I'll try it, hope it helps others too.


Pardon me for being nitpicky, but I resent phrases that suggest that fiddling with time zones results in more (or less) daylight in a given day.
Above, the author says, "Even though cities like this are on the same clock, the western city gets roughly an hour more of sunlight..." The number of hours of daylight is affected by your latitude, but not by your longitude. Two cities at the same latitude will get exactly the same amount of daylight in a given day. The difference that the author is talking about is that the sun will rise and set earlier on the eastern edge of a time zone than it will on the western edge.
In the same way, Daylight Savings Time does not give more hours in a day. It justs adjusts our clocks so that we experience a later sunrise and sunset.
But in all cases the number of hours of daylight remains the same.


The researcher in India should realize that the CAPTCHA breaking employees are not "double checking" answers. The computer that generated the image knows the answer. These people are helping spammers get access to Internet forums. It doesn't change the research, but she should know who she is dealing with.


I would love to know the other factors considered when comparing cities to determine the change in income based on sleep. I recently relocated to a city full of over-educated, under-employed 30-somethings but very little in the way of industry. The salaries definitely reflect the low supply of jobs and abundance of workers. I have to imagine those are more influential than the sunset.

Darin Dunham

I would think that those living in the eastern part of a time zone are getting up earlier and thus getting the early worms, as opposed to sleeping more to increase income.


It is a false comparison to compare Hunstville (Rocket City) to Amarillo. Huntsville has arguably the highest concentration of Science Ph.D.'s in the country per capita. It is not surprising it has a higher median income then a modestly educated Amarillo. If you want a comparable city at that latitude, than Los Alamos is a better comparison.

Martie Eckstein

The tip for earplugs is a good one. I want to elaborate on the proper way to wear and remove earplugs.
1. Roll he ear plug in your fingers, to squash it down.
2. Put hand over back of head, grab opposite ear, and pull up to open the ear canal
3. Insert ear plug, them hold you finger on the ear plug while it expands into your ear canal.
To test, cup your hands over your ears and you should notice no difference in sound.

When removing the ear plug make sure you do it slowly and turn it.
CDC has information on it on their website and YouTube has some good videos as well.


While working in London (very high North, where it starts to get dark at 3PM in the Winter!!) I had my office all download a plug-in for their computers (F.Lux) that changed the colour temperature of the screens. I.e. as the sun gradually set, the screens shifted from blue light to orange light. Everyone reported to feeling better and having less strain on their eyes.

At night, I watch movies on my computer because of this plug-in, and sleep much better.

I'm shocked that this hasn't been developed for phones yet (at least, iPhones)! It would be great for Freakonomcis to issue a Call To Action to develop something similar for phones (please!)


Why not look at some studies in Spain where the entire country is in the incorrect time zone....


Part 3 should focus on the QUALITY of sleep. You can have your eyes closed for 8 hours, but was it quality? Check out Shawn Stevenson's book: Sleep Smarter

James Schneider

This study is probably bunk not only does NASA have a large presence in Huntsville, but as does Boeing, and the United States Army Ordnance Center. The study can be disproven by simply looking at the average job of individuals in their cities. Huntsville- US Army, Amarillo -Teachers, those army employees are making more by default and it was not account for in their study. If I had more time I would write to the publican eschewing, but it would behoove freakonomics to at least mention this fact in their article or in a future show.


As someone that worked at several offices with "flex time", I'd be interested to see how much work is done by people that are early risers and get to work at 6:00am-7:30am versus those that arrive later in the day, 8:00am to 9:00am. From what I have seen, nothing useful gets done until 9:00am to 10:00am anyways. Those that arrive early tend to sit around and do nothing until 9:00am. Those that arrive at 8:00am to 9:00am, come in and get to work. I'm also interested to see what the quality of the work done by those groups is too.

Sarah Selhorst

Thank you for this!

I have been complaining for years that the world favors the morning-bird and prejudices them as more industrious, healthy and productive.

I would suspect that what happens often, as in my case, is that workers take their workload home with them, to tackle when energized, resulting in a relatively unproductive morning and more "off-the-clock" performance.

It's frustrating when your 9-5 becomes a 9-2am, when it might just as well be noon-8.


Why are we still doing this dance?

Work stress and schedules are the ONLY cause’s of insomnia today.

Employee’s don’t decide when to wake up or go to bed, their employer does. So even if someone’s body works better, going to bed, say at 2AM and then waking up at 10AM, it doesn’t matter because the job dictates when sleep happens, or at the very least when a person MUST wake up. Its not up to the individual, their biological clock or even their physician to determines when “sleep happens”.

So, can we please stop dancing around the real causes for people not getting enough sleep in America?

The problem is the way we earn money, how we are employed and how “job creators” can dictate lifestyles, PERIOD!


Instead of buying yellow tinted glasses you can get this app that automatically adjusts your screens color at night to have less blue.


It is stated that by increasing the amount of sleep for everyone in a city, the average wage increased. Is there a possibility that simply the fact that, for whatever reason, that city on average has a slightly higher income, and that is the reason that they get more sleep. With a higher wage, it allows for people to have slightly more security, which means they worry about money less and how they will pay for things, so this allows them to sleep better. I think it is possible that the connection made between these things are not what is presented. Where is the break point for this as well? At what place does any additional sleep not provide any benefit, either physically or financially? I know there is one financially, because it would be impossible to sleep all day, and make more money, so to say that more sleep provides a financial increase can not be completely factual.


From the podcast, it is evident that increases in sleep duration also increase wages earned. In turn, would an increase in sleep then increase both the GDP of a country, and CPI?