From the academic paper linked to in that news article
> the hours at which output is a maximum is at 67 and at 64, respectively. In fact, there are a few cases in which actual observations on hours of work exceed 67 and 64 meaning that, in these instances, average observed hours were at levels where the estimated marginal product of hours is negative!
In repetitive work of course more time is always gonna be more productive, with diminishing returns. Until the worker/slave mind or body breaks at least.
Mind you, I'm not saying the same doesn't apply for knowledge workers. Just that this specific articles doesn't provide evidence for knowledge workers.
I imagine that there will be more science being done for productivity on knowledge workers once there's some decent way of measuring productivity for knowledge workers.
My original claim was that there’s no research showing negative productivity for any job for less than 60 hours a week of work. If you have anything to the contrary please share.
There is no reason to believe knowledge workers are any different than manual workers here. Your productivity turns negative when you make so many mistakes that you’re destroying value, not creating it. The article may be only weak evidence for knowledge workers but it certainly isn’t no evidence. Other forms of evidence while not rising to the standards of publication certainly don’t point to 40 hours work a week being optimal for productivity of most knowledge workers. Physicians, professors at research institutions, top tier lawyers, all these people work insane hours.
There is no evidence that working less than 60 hours a week is better for productivity, anywhere, just a bunch of people wishing really hard.
> Your productivity turns negative when you make so many mistakes that you’re destroying value, not creating it.
One thing to consider about knowledge/skill workers vs unskilled labor is that most complex systems are house of cards style situations where a single mistake can both destroy a network effect of value, but also take several orders of magnitude of time and effort to detect and rectify the actual issue.
Introducing a subtle, but value destroying, bug into a system can do value damage to the N systems it interconnects with, and can lead to a near total loss of the whole system (eg: drop table). Of course there are safeguards that can help avoid this like backups, but still the point is a carpenter wouldn't make the whole house worthless by a misplaced nail.
Because manual workers and knowledge workers get mentally weary in the same way and make mistakes in the same way, using their brains. Your muscles are perfectly capable of going longer. Your attention span, working intelligence and executive function are going to get messed up whether you’re putting 60 hours into putting the right amount of powder into every container or checking the Excel formulas are all correct.
Manual laborers are people no less than accountants or mathematicians.
Ok, there’s just so many facts contrary to all normal experiences, so I’d like to see some sources. For example, I can easily work twelve hours per day while painting the facades of my home, without being mentally fatigued, only bored. But my body is surely sore after climbing up and down stairs all day. On the other hand, I’m hardly capable of doing six hours of really focused mental work per day.
> the hours at which output is a maximum is at 67 and at 64, respectively. In fact, there are a few cases in which actual observations on hours of work exceed 67 and 64 meaning that, in these instances, average observed hours were at levels where the estimated marginal product of hours is negative!
http://ftp.iza.org/dp8129.pdf
The Productivity of Working Hours John Pencavel April 2014
I believe this is in line with what I wrote
> I have never seen any research showing net negative productivity for any job for under 60 hours a week of work.