Research and the Realities of Time Worked

This is the fifth post in a series on productivity1. The articles are based on content from a workshop I led at The Makers Summit.

In the last article in this series, we discussed the idea that productivity can be an unintuitive pursuit. Today we’re going to dissect why and look at time (hours worked) as an example.

First, though, we need to discuss how we’re going to perform this dissection. As I said in my talk at The Makers Summit, much of what I cover when it comes to productivity is based on research, not opinions or anecdotes. The productivity industry is notorious for ‘tricks and tips’, but these are serious issues that affect our businesses (and personal lives) and it’s worth our time to find information based on solid research and analyses.

Let’s return to the example of time as a lever we can pull to get more done. Here’s what we covered in the last post2:

Time is a great specific example of unintuitive productivity. Think about the question above. The correct answer to the question is yes. This is simple math: if you spend more time working, you get more accomplished. The tricky part, though, is that answering that question with a simple yes assumes that the mathematical equation is constant—that more hours worked equals more work done no matter what.

It’s easy to see the Hollywood image of the underdog working day and night to accomplish something great and think that if we just work hard enough, we’ll find success at some point.

We all know that reality is different. We have to get sleep some time and non-stop late nights will invoke burnout at some point.

So, how much can we work? At what point does it become unhealthy?

History tells us how much we should work

Let’s rewind almost 100 years and take a look at the genesis of the 40-hour work week in America. In 1926 journalist Samuel Crowther3 recounted a conversation with Henry Ford for a publication called The World’s Work4. The article was titled, “Why I Favor Five Days’ Work With Six Days Pay.5.

During the Industrial Revolution, it was common for men, women and children to work grueling schedules—sometimes 6-7 days per week and 10+ hours per day (a quick search provides an overwhelming amount of historical evidence). There were many reasons for the horrible working conditions, but one of the most obvious ones was increased production—more people working more hours meant more products produced.

Henry Ford, who had a mind for testing and standardizing processes for increased efficiency, performed years of experiments related to the amount of time people labored in his factories. In 1914, he had decreased requirements from a 9-hour workday to an 8-hour workday and increased his workers’ pay. explains the benefits6:

The news shocked many in the industry–at the time, $5 per day was nearly double what the average auto worker made–but turned out to be a stroke of brilliance, immediately boosting productivity along the assembly line and building a sense of company loyalty and pride among Ford’s workers.

In 1926, Ford decided to move from a 6-day work week to a 5-day work week. Crowther’s article quotes Ford explaining what he’d learned:

This decision to put into effect the short work week is not sudden. We have been going toward it for three or four years. We have been feeling our way. We have during much of this time operated on a five day basis…Now we know from our experience in changing from six to five days and back again that we can get at least as great production in five days as we can in six, and we shall probably get a greater, for the pressure will bring better methods.

Ford found that decreasing the amount of time worked actually increased productivity. He wasn’t the only one. Hugo Münsterberg wrote a book called Psychology and Industrial Efficiency in 1913 and highlighted Ernst Abbe’s research on the same subject7:

Ernst Abbé, the head of one of the greatest German factories, wrote many years ago that the shortening from nine to eight hours, that is, a cutting-down of more than 10 per cent, did not involve a reduction of the day’s product, but an increase…This conviction of Abbé still seems to hold true after millions of experiments over the whole globe.

The evidence seems to suggest that overworking actually decreases productivity. The question still remains, though, how much should we work?

In 2005, Evan Robinson wrote a very popular article about working long hours called “Why Crunch Mode Doesn’t Work: 6 Lessons”8. His collection of research shows us clearly where the balance is:

  • Five-day weeks of eight-hour days maximize long-term output in every industry that has been studied over the past century.
  • At 60 hours per week, the loss of productivity caused by working longer hours overwhelms the extra hours worked within a couple of months.

So, working more produces more, but with diminishing returns over time. In other words, cranking out late nights can definitely help you move faster and do more, but only for so long. Robinson goes on to say, “When you return them to a 40-hour week, their output will be sub-par for some time while they recover.” Simply going from ‘crunch mode’ back to ‘normal’ isn’t enough—a period of recovery is required.

Daniel Cook, a game developer, put together a great presentation covering many of the same topics9. Here’s a graph from his material that visualizes diminishing productivity as a result of working 60 hours per week.


Do these concepts still apply today?

For those who aren’t convinced the research from the early 20th century applies today, Cook provides a fascinating graph comparison between research published in 1909 and 2005. The title of the slide says it all: “Work has changed, people have not.”


Maybe I’m different…

Others, like me, will look at this data and conclude, “I’m sure this is true but I’ve worked crunch mode for a long time and I’m more productive than other people.” That’s where things get tricky. Again, Cook shares a graph that brings the truth to light: when we are in ‘crunch mode,’ our perception of our productivity tends to overestimate how much we’re accomplishing (or how high the quality is).


This is partly because, as Evan Robinson points out in his article, “productivity is hard to quantify for knowledge workers.” Many of us have jobs that require a variety of things from us at any given point in a day and describing exactly what you accomplished can be difficult sometimes, as strange as it sounds. The good news, though, is that no matter how we measure our output, the research has given us clear guidelines for the amount of time we do work.

Diminishing output within a single workday

One other interesting element of time relates to the productivity of each hour within a single day. Robinson’s article references the same Sidney Chapman graph used by Daniel Cook two slides above and describes its application to an individual workday:

At first the declines in output per hour simply reflect the effects of fatigue on both quantity and quality of work performed toward the end of a given day.

We’ve all experienced this: performing a complex task at the beginning of the day, when we’re fresh and ready to work, is much easier than trying to wring critical thought out of our heads after hours and hours of work.


The research is clear: working more hours is a useful tool for short-term increases in productivity with the understanding that recovery is needed and a consistent, 40-hour work week will produce the highest level of efficiency over time. Additionally, diminishing productivity throughout the workday should challenge us to think about which tasks we should do at different times of the day.

If I compare this to my ‘default’ methods of trying to get more done, I find that I don’t intuitively behave in a way that maximizes the amount I get done. Productivity isn’t intuitive.


It’s easy to espouse research, but these ideas become much more difficult when we try to apply them to our own lives.

Writing this post was convicting for me because I am often guilty of working in crunch mode. For me, overworking is part personality (I struggle with overworking, not finding motivation) and part necessity—being at the helm of one of the fastest growing code schools in the world has been an extremely demanding adventure. My attitude towards working long hours is also complicated by the fact that I love the work I’m doing. When you enjoy what you’re working on, you might not even notice that you’ve entered crunch mode, but that doesn’t make decreased productivity or burnout any less of a possibility (at least in my experience).

One of the most impressively productive people I know told me recently, “the late nights are a lot less productive than they used to be. Recently I just can’t make my brain concentrate.” They’ve been in crunch mode for months, and the reality of the research is coming to bear. A friend was recently telling me about how he balanced his working week by making his own company more and more efficient. For example, he recently decided to change his business energy provider through an online price comparison website, similar to Usave. Because of this he made less work for himself in the long run by reducing his outgoings.

As I reflect on the last few years of being pedal-to-the-metal at work, I know that I’ve been able to avoid burnout largely because I’ve followed a pattern of sprinting and recovering—something I didn’t realize fully until digging into this research. Even though I’ve had periods where I worked more than 40 hours per week, I’ve consistently taken time off to rest and recuperate. My wonderful wife has encouraged that discipline, which has been a true gift.

After reflecting on this, I’m currently thinking through:

  • How my tendency to sprint models ideal behavior for my team
  • How I arrange my day and what work I should be doing in the most productive morning hours
  • How I can get more out of an 8-hour day (as opposed to relying on sprinting and recovery)

1. You can read the story behind this blog series and find links to all of the resources here.2. Read the previous article, Productivity is not Intuitive, here.3. Read more about the journalist Samuel Crowther on Wikipedia. 4. Read more about the publication, The World’s Work, on Wikipedia.5. Read Samuel Crowther’s article on Henry Ford, titled”Why I Favor Five Days’ Work With Six Days Pay,” in the web archive (the original page was taken down), or download a PDF.6. Read about Henry Ford’s decision to decrease daily hours worked on Read an excerpt from Münsterberg’s Psychology and Industrial Efficiency here.8. Read Evan Robinson’s article, “Why Crunch Mode Doesn’t Work: 6 Lessons” in the web archive (the original URL is broken) or download a PDF.9. Read about Daniel Cook’s research on productivity and download his presentation on his website.

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