<p>The closest study I could find was that by John Pencavel titled '<a href="http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2429648" rel="nofollow">The Productivity of Working Hours</a>.'</p>

<p>Abstract:</p>

<blockquote>
  <p>Observations on munition workers, most of them women, are organized to examine the relationship between their output and their working hours. The relationship is nonlinear: below an hours threshold, output is proportional to hours; above a threshold, output rises at a decreasing rate as hours increase. Implications of these results for the estimation of labor supply functions are taken up. The findings also link up with current research on the effects of long working hours on accidents and injuries.</p>
</blockquote>

CC BY-SA 3.0
2015-08-28T14:07:32.780Z
2015-08-29T03:13:34.683Z
2015-08-29T03:13:34.683Z
ChinG
<p>The list of references is long. Below some citations from <a href="https://cris.maastrichtuniversity.nl/portal/files/11867448/content" rel="nofollow noreferrer">this</a> 2017 article:</p>

<blockquote>
  <p>Studies estimating production functions
  based on industry-level data find mixed evidence for the returns to working
  hours. Whereas some studies find increasing returns to hours (Feldstein,
  1967; Craine, 1973; Leslie, 1984), which could be the result of not taking
  capacity utilisation rates into account (e.g. Tatom, 1980), or be due to aggregation
  bias (e.g. DeBeaumont and Singell, 1999), other studies conclude
  that output is roughly proportional to hours worked per worker (Hart and
  McGregor, 1988; Anxo and Bigsten, 1989; Ilmakunnas, 1994). The majority
  of studies, however, find evidence of decreasing returns to hours (e.g. Leslie
  and Wise, 1980; Tatom, 1980; DeBeaumont and Singell, 1999; Shepard and
  Clifton, 2000).</p>
  
  <p>A few studies use panels of firms to estimate the link between
  working time and firm or establishment productivity (Crepon et al., 2004;
  Schank, 2005; Kramarz et al., 2008; Gianella and Lagarde, 2011). They
  tend to find that output is roughly proportional to the number of hours
  worked.</p>
  
  <p>Studies using data about individual workers in a firm, or about workers
  in comparable firms date back to the early 20th century [...]  (Goldmark,
  1912; Vernon, 1921; Kossoris, 1947). More recently, [...] Crocker and Horst (1981) find that output is proportional
  to hours worked, Brachet et al. (2012), Pencavel (2015), and Dolton et al.
  (2016) find evidence of decreasing returns to hours. A contrasting result is
  found by Lu and Lu (2016).</p>
</blockquote>

<p>That same article is the latest paper available on the topic, which also finds a negative effect of working hours on productivity, this time for call-centre workers.</p>

<p>There is also this quote from a New Economics Foundation <a href="http://neweconomics.org/wp-content/uploads/2016/10/BUILDING_A_NEW_ECONOMY.pdf" rel="nofollow noreferrer">report</a>:</p>

<blockquote>
  <p>In Gothenburg, Sweden’s second largest
  city, workers at the
  Svartedalens retirement home and
  the Toyota car factory have been
  working a 30-hour week. Nurses
  at the care home who worked
  six-hour days were happier than
  a comparable group on standard
  hours, and had more energy at
  work and in their spare time. They
  took half as much sick leave and
  were able to spend much more time
  undertaking activities with residents.
  At the Toyota factory, where a
  30-hour week was introduced a
  decade ago, staff now produce in 30
  hours 114% of what they used to
  produce in 40 hours. These results
  are encouraging other employers, in
  Sweden and elsewhere, to reduce
  working hours.  </p>
</blockquote>

<p>Unfortunately, they do not provide the references.</p>

CC BY-SA 3.0
2017-08-23T06:31:48.850Z
2017-08-23T06:31:48.850Z
luchonacho
<p>It might be interesting for you to compare different countries. French and German workers for example have worked less and less hours per year in the last decades whereas in the UK and US it has remained relatively stable. Only in UK has productivity not increased substantially from 2000-2015. For many years US labor productivity was below that of France and Germany. This has changed since 2000 (I presume the global crises played a major role but I am not an expert). Cf. <a href="http://piketty.blog.lemonde.fr/2017/01/09/of-productivity-in-france-and-in-germany/" rel="nofollow noreferrer">Thomas Piketty, 9 January 2017, "Of productivity in France and in Germany"</a></p>

CC BY-SA 3.0
2017-08-23T18:09:14.103Z
Welcome to Econ.SE! Such aggregate analysis however is very unlikely to reflect causality.
luchonacho
CC BY-SA 3.0
2017-08-23T17:53:34.970Z
2017-08-23T17:53:34.970Z
Econstudent
<p>This question, as is, does not particularly describe a well-defined hypothetical.</p>

<p>Am I paying people a higher rate for more hours? The change in productivity might be a net positive or negative if wages rise, depending on the time allocation of the worker. Where is the change in working hours happening? If I go from 1 minute of work to 1 hour of work, productivity would presumably increase because of the time it takes to get into a state of mind to work.</p>

<p>These kinds of things that are needed to answer your question is related to the <strong>time allocation of labor, leisure, and household work</strong> as posited by <a href="http://www.jstor.org/stable/2228949" rel="nofollow noreferrer">Gary Becker in 1965</a>. It has been revisited again by <a href="http://agecon2.tamu.edu/people/faculty/capps-oral/agec%20635/Readings/Leisure,%20Home%20Production,%20and%20Work%20the%20Theory%20of%20the%20Allocation%20of%20Time%20Revisited.pdf" rel="nofollow noreferrer">Gronau, 1977</a> and so on. If I am increasing working hours, I have to decrease activity in household production and leisure, so in order to say whether productivity increases if working hours increase, you have to answer what causes the marginal value of work to increase so that people willingly take on more work and less leisure.</p>

<p>If something like a technological advancement makes it easier for me to work, I may become more productive, but willingly take on less hours to do my work if I am on a salary/commission. This does mean the inverse, that more hours would make me less productive per se, would be true. If I am on a hourly rate, technology that makes it easier to work changes my marginal cost of effort, which changes the opportunity cost of leisure or household work. So maybe I'll take on more work in this case and become more productive.</p>

<p><em>The question isn't whether higher working hours decreases productivity. The question is why workers change working hours, and whether those voluntary changes overlap with productivity changes. The "effect" of extra hours on productivity, is ambiguous.</em></p>

CC BY-SA 3.0
2017-08-23T14:26:24.773Z
I think the question is pretty clear, and it is asking for references, not for an explanation of the underlying theory(ies). That is a different question altogether.
luchonacho
CC BY-SA 3.0
2017-08-23T14:42:55.453Z
My point is you can't answer the question (carefully) without discussing confounding effects. The user states the hypothetical as "there is more time spent on building machines with the same amount of money". What does this mean? Same money per hour? Same salary and no extra pay? But more importantly, how can you decompose worker effort without knowing what causes the increase in hours?
Kitsune Cavalry
CC BY-SA 3.0
2017-08-23T14:44:36.520Z
At any rate, other answers give references for their approach to the answering questions related to the question formulated by the user. I'm not going to rehash them. I'm giving my own take on the question and offering my own references, claiming that the effect of extra hours is ambiguous, as the question stands.
Kitsune Cavalry
CC BY-SA 3.0
2017-08-23T15:12:21.313Z
The papers cited do explain some of the context, particularly when it comes to endogeneity, which is what you are referring to in the second-to-last paragraph. The OP did however provide in the edit, as you say, an ambiguous hint of what the hypothesis is. That is probably more suited for a second question, which deserves a full answer in itself.
luchonacho
CC BY-SA 3.0
2017-08-23T15:18:09.420Z
It'd be very well and fine if there were a separate, more refined question. I do not think the OP's hypothesis was very clear for me personally, hence my broader answer.
Kitsune Cavalry
CC BY-SA 3.0
2017-08-23T14:22:09.827Z
2017-08-23T14:45:21.277Z
2017-08-23T14:45:21.277Z
Kitsune Cavalry
<p>Are there studies about the impact on per-hour output (productivity) of increasing the number of hours worked each week by employees? If every employee works 3hrs/week longer (from 41 to 44hrs), does productivity  increase or decrease?</p>

<p><strong>Edit</strong>
About who and how much; if every worker works 3hrs more. So there is more time spent on building machines with the same amount of money. But my hypothesis is, that the more time demotivation overcompensates this marginal plus.</p>

CC BY-SA 3.0
2017-08-23T15:10:09.577Z
Some years ago I came across EU studies on this, as well as ILO materials - can be a good source to check!
JoaoBotelho
<reference-request><labor-economics><productivity>
Can higher working hours reduce productivity?
Sider
# Can higher working hours reduce productivity?

(Asked by: username_0 on 2015-08-13)

Are there studies about the impact on per-hour output (productivity) of increasing the number of hours worked each week by employees? If every employee works 3hrs/week longer (from 41 to 44hrs), does productivity increase or decrease?

**Edit**
About who and how much; if every worker works 3hrs more. So there is more time spent on building machines with the same amount of money. But my hypothesis is, that the more time demotivation overcompensates this marginal plus.

**Tags:** reference-request, labor-economics, productivity

> **Comments:**
> **username_1**: Some years ago I came across EU studies on this, as well as ILO materials - can be a good source to check!  

---

## 4 answers

### Answer by username_2 on 2015-08-28. Score: 3

The closest study I could find was that by John Pencavel titled '[The Productivity of Working Hours](http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2429648).'

Abstract:

> Observations on munition workers, most of them women, are organized to examine the relationship between their output and their working hours. The relationship is nonlinear: below an hours threshold, output is proportional to hours; above a threshold, output rises at a decreasing rate as hours increase. Implications of these results for the estimation of labor supply functions are taken up. The findings also link up with current research on the effects of long working hours on accidents and injuries.


---

### Answer by username_3 on 2017-08-23. Score: 0

The list of references is long. Below some citations from [this](https://cris.maastrichtuniversity.nl/portal/files/11867448/content) 2017 article:

> Studies estimating production functions
> based on industry-level data find mixed evidence for the returns to working
> hours. Whereas some studies find increasing returns to hours (Feldstein,
> 1967; Craine, 1973; Leslie, 1984), which could be the result of not taking
> capacity utilisation rates into account (e.g. Tatom, 1980), or be due to aggregation
> bias (e.g. DeBeaumont and Singell, 1999), other studies conclude
> that output is roughly proportional to hours worked per worker (Hart and
> McGregor, 1988; Anxo and Bigsten, 1989; Ilmakunnas, 1994). The majority
> of studies, however, find evidence of decreasing returns to hours (e.g. Leslie
> and Wise, 1980; Tatom, 1980; DeBeaumont and Singell, 1999; Shepard and
> Clifton, 2000).
>
> A few studies use panels of firms to estimate the link between
> working time and firm or establishment productivity (Crepon et al., 2004;
> Schank, 2005; Kramarz et al., 2008; Gianella and Lagarde, 2011). They
> tend to find that output is roughly proportional to the number of hours
> worked.
>
> Studies using data about individual workers in a firm, or about workers
> in comparable firms date back to the early 20th century [...] (Goldmark,
> 1912; Vernon, 1921; Kossoris, 1947). More recently, [...] Crocker and Horst (1981) find that output is proportional
> to hours worked, Brachet et al. (2012), Pencavel (2015), and Dolton et al.
> (2016) find evidence of decreasing returns to hours. A contrasting result is
> found by Lu and Lu (2016).

That same article is the latest paper available on the topic, which also finds a negative effect of working hours on productivity, this time for call-centre workers.

There is also this quote from a New Economics Foundation [report](http://neweconomics.org/wp-content/uploads/2016/10/BUILDING_A_NEW_ECONOMY.pdf):

> In Gothenburg, Sweden’s second largest
> city, workers at the
> Svartedalens retirement home and
> the Toyota car factory have been
> working a 30-hour week. Nurses
> at the care home who worked
> six-hour days were happier than
> a comparable group on standard
> hours, and had more energy at
> work and in their spare time. They
> took half as much sick leave and
> were able to spend much more time
> undertaking activities with residents.
> At the Toyota factory, where a
> 30-hour week was introduced a
> decade ago, staff now produce in 30
> hours 114% of what they used to
> produce in 40 hours. These results
> are encouraging other employers, in
> Sweden and elsewhere, to reduce
> working hours.

Unfortunately, they do not provide the references.


---

### Answer by username_4 on 2017-08-23. Score: 0

It might be interesting for you to compare different countries. French and German workers for example have worked less and less hours per year in the last decades whereas in the UK and US it has remained relatively stable. Only in UK has productivity not increased substantially from 2000-2015. For many years US labor productivity was below that of France and Germany. This has changed since 2000 (I presume the global crises played a major role but I am not an expert). Cf. [Thomas Piketty, 9 January 2017, "Of productivity in France and in Germany"](http://piketty.blog.lemonde.fr/2017/01/09/of-productivity-in-france-and-in-germany/)

> **Comments:**
> **username_3**: Welcome to Econ.SE! Such aggregate analysis however is very unlikely to reflect causality.  

---

### Answer by username_5 on 2017-08-23. Score: 0

This question, as is, does not particularly describe a well-defined hypothetical.

Am I paying people a higher rate for more hours? The change in productivity might be a net positive or negative if wages rise, depending on the time allocation of the worker. Where is the change in working hours happening? If I go from 1 minute of work to 1 hour of work, productivity would presumably increase because of the time it takes to get into a state of mind to work.

These kinds of things that are needed to answer your question is related to the **time allocation of labor, leisure, and household work** as posited by [Gary Becker in 1965](http://www.jstor.org/stable/2228949). It has been revisited again by [Gronau, 1977](http://agecon2.tamu.edu/people/faculty/capps-oral/agec%20635/Readings/Leisure,%20Home%20Production,%20and%20Work%20the%20Theory%20of%20the%20Allocation%20of%20Time%20Revisited.pdf) and so on. If I am increasing working hours, I have to decrease activity in household production and leisure, so in order to say whether productivity increases if working hours increase, you have to answer what causes the marginal value of work to increase so that people willingly take on more work and less leisure.

If something like a technological advancement makes it easier for me to work, I may become more productive, but willingly take on less hours to do my work if I am on a salary/commission. This does mean the inverse, that more hours would make me less productive per se, would be true. If I am on a hourly rate, technology that makes it easier to work changes my marginal cost of effort, which changes the opportunity cost of leisure or household work. So maybe I'll take on more work in this case and become more productive.

*The question isn't whether higher working hours decreases productivity. The question is why workers change working hours, and whether those voluntary changes overlap with productivity changes. The "effect" of extra hours on productivity, is ambiguous.*

> **Comments:**
> **username_3**: I think the question is pretty clear, and it is asking for references, not for an explanation of the underlying theory(ies). That is a different question altogether.  
> **username_5**: My point is you can't answer the question (carefully) without discussing confounding effects. The user states the hypothetical as "there is more time spent on building machines with the same amount of money". What does this mean? Same money per hour? Same salary and no extra pay? But more importantly, how can you decompose worker effort without knowing what causes the increase in hours?  
> **username_5**: At any rate, other answers give references for their approach to the answering questions related to the question formulated by the user. I'm not going to rehash them. I'm giving my own take on the question and offering my own references, claiming that the effect of extra hours is ambiguous, as the question stands.  
> **username_3**: The papers cited do explain some of the context, particularly when it comes to endogeneity, which is what you are referring to in the second-to-last paragraph. The OP did however provide in the edit, as you say, an ambiguous hint of what the hypothesis is. That is probably more suited for a second question, which deserves a full answer in itself.  
> **username_5**: It'd be very well and fine if there were a separate, more refined question. I do not think the OP's hypothesis was very clear for me personally, hence my broader answer.  

---

