[rascul]

> - A 20% reduction of work time never amounts to a 20% reduction of productivity or work output, unless the work consists solely of sitting in a chair (and that's not counting bathroom breaks).

I don't understand what you're saying here. If I work 20% less then that's 20% less work that I get done. I don't sit in a chair for work.

[truckerbill]

Your assumptions only work when things are linear. Reality is generally non-linear as it is one huge tangled mess of feedback loops

[rascul]

I only have my own work history to go off of.

Edit: An example. If it takes me 5 days to hang siding on a house, and I don't work one of those days, that's 20% less I didn't work and about 20% less of the work that got done.

[truckerbill]

Lets say you have enough spare time and energy to make a jig, a trolley, an improved tool of some kind that helps you hang siding. For the time you spend making it you are behind on your general average siding panels per day. Once you finish your tool you will surpass your average. This is one of many many non-linear holes in your theory.

You may say 'but you can't guarantee I will make a jig, a trolley or an improved tool', at which point I give up trying to argue with someone on the internet and feel slightly deflated that the point was missed

[rascul]

> Lets say you have enough spare time and energy to make a jig, a trolley, an improved tool of some kind that helps you hang siding. For the time you spend making it you are behind on your general average siding panels per day. Once you finish your tool you will surpass your average. This is one of many many non-linear holes in your theory.

I like this. Thank you for providing me some more understanding.

[truckerbill]

You’re welcome :)

[fnordian_slip]

Iirc, there are several of studies that imply that if you have the same developer working 40 vs 32 hours, the difference in output is often negligible, since not all hours worked are the same in terms of effectiveness.

You might not be aware of that effect, since you deny it explicitly when it comes to your own work, but you might view it in a different light if you turn it around:

Would you produce twice as much if you were to work 80 hours? Probably not, right? You'd maybe produce about 1.5 times as much, and the quality of your work would suffer greatly, leading to more work in the future.

The same effect might work in the other direction, up to a certain point.

The 40 hour work week is not god-given, in fact it has been reduced quite a number of times in the past (mostly due to unions, like most working condition improvemens). So I can not understand why so many people act as if it were set in stone.

[rascul]

> Iirc, there are several of studies that imply that if you have the same developer working 40 vs 32 hours, the difference in output is often negligible, since not all hours worked are the same in terms of effectiveness.

I guess it depends on the work. In my example, hanging siding on a house, the non-productive work is quite minimal. I guess that can vary depending on the work one is doing. The non-productive work still needs to get done so the productive work can get done, though.

> Would you produce twice as much if you were to work 80 hours? Probably not, right? You'd maybe produce about 1.5 times as much, and the quality of your work would suffer greatly, leading to more work in the future.

I doubt many people can sustain their work output over 16 hours for most jobs. But that's not really what we're talking about here.

> The same effect might work in the other direction, up to a certain point.

Sure, if you work faster when you work less hours. Are you saying this is what happens? Are you seeing people get too fatigued after 6 hours of work so that their productivity is diminished? I've not seen that in general with the people I've worked with or the work I do over the years.

> The 40 hour work week is not god-given, in fact it has been reduced quite a number of times in the past (mostly due to unions, like most working condition improvemens). So I can not understand why so many people act as if it were set in stone.

I'm not sure where this came from because I don't think any of those things. I think that the only way for work to get done is to do it. However many hours per week that takes is fine. I don't understand the argument that working less doesn't mean you get less work done in general.

All that said, I realize there might be something different to brain fatigue vs body fatigue when doing brain work (software development) vs physical work (construction). I've largely done physical work and can't relate well to brain work except as a hobby and occasional small bits of work.

[fnordian_slip]

You're quite right that there's quite a difference when it comes to physical work, especially not too physically demanding work without a large "brain work" component (or done by young, reasonably fit people).

Since we are on hacker news, a forum seemingly overrun by silicon valley devs, I didn't expect your comment to focus on that kind of work. But when we look at physically demanding work with a decent amount of brain work, for example some kinds of woodworking, you can still see that effect. People can work longer hours and more days to a certain extent, but then the rate of accidents goes up (and I'd expect it to behave in a non-linear fashion). And if that effect is true in that direction, why should it not work for less than 40 hours?

> I doubt many people can sustain their work output over 16 hours for most jobs. But that's not really what we're talking about here.

Apparently, I'm no good at making myself clear. It's probably the language barrier, I'm decent enough at understanding English, but I lack any sort of conciseness, I believe. This was meant to be an extreme example, to make the point more obvious, but let's use a similar, more normal one.

Let's say instead of moving to a 4 day workweek, we move back to a 6 day workweek. Daniel you believe that you get 20% more output than before? Even with physical jobs that don't involve too much brainwork, I believe that this is not the case, as there are diminishing returns when the time for recreation is cut too short.

That depends on the individual of course, younger people need less than older people in general, and things like children, disabilities, a long commute and a host of other factors can change the equation, too.

> I don't understand the argument that working less doesn't mean you get less work done in general.

The argument is basically that for brain work, if you spend 20% more time per week at work, you might only produce less than 5% more output, since your brain will otherwise produce too many errors, which cost time to correct.

That is seen as an inefficient use of an employee's time. Also, his implies that maybe we could get almost the same output from people who work a 4-day-workweek. Now the question is, where is the sweet spot, as it is unlikely to be the status quo (that's what I clumsily tried to imply with the remark about the 40-hour-workweek not being"god-given")? This can't scale forever, of course, or we'd all be working 1 hour a week and be extremely productive in that hour :D

But maybe the 4-day-workweek is that sweet spot. And since wages haven't kept up with corporate profits for a while, a lot of people - myself included - are eager to find out.

[rascul]

Thank you for entertaining my arguments. I like that we have a lot of different people with different backgrounds, experiences, and opinions on HN which we can share with each other. I'm not much interested in continuing the discussion anymore but I do feel as if you have opened my mind a bit.

[whstl]

20% reduction of work is not working 20% less. It's working 20% less time.

Productivity and time aren't correlated.

[rascul]

They are largely correlated in just about all work that I've done. Is your experience different?

[whstl]

Yes. Heavily.

Even in cases such as manual work it doesn’t have a directly proportional correlation, since people get tired.

[rascul]

Yes people get tired but I don't see that significantly affecting the amount of work done in general, for 8-9 hour work days. Do you?

[whstl]

Yes, definitely. It also heavily affects the quality.