The Productivity of Working Hours (2014) [pdf]
ftp.iza.org
ftp.iza.org
* The collected data is from 1915-1920
* The collected population is very very small
(most sets are less than 50 individuals, one is ~100)
* The work performed by the population is extremely repetitive manual labor
With these caveats, it is safe to say that most of the audience of HN has nothing to gain from the results of this study.The fact that the data is from 1915 - 1920 does not invalidate it unless you want to suggest that human nature in 1915-1920 is different than it is now - which would seem a strange point to defend. And the sample sizes are quite decent.
I know that the HM userbase had a tendency to dismiss studies that are incorrectly conducted, but I don't think that this is one of those cases.
Finally almost nobody who reads HN does repetitive manual labour. Manual productivity is very different from mental productivity.
From my own experience, I'm not even productive for 40 hours per week. Let alone working 50 hours consistently every week.
I do believe that there are diminishing returns in software development (and startups) but a lot of it depends on the type of job, stage of company, existing support processes, etc.
That information I think would be more compelling to an employer (or self-employer), because without it, you're simply saying 'You'll get more out of overworking people, you just won't get as much more.'
Which still reads like "more."
Software specifically is too variable to accurately measure productivity. It's too subjective. Not only from a personal point of view, but also dependent on the task. Given the tendency towards automating the boring tasks, it seems that conducting such a study in the software development world becomes less and less likely.
One can argue that frequent interruptions from these sources gives workers the opportunity to 'micro-recharge'.