I'd like to note the sheer volume of people in the wider startup ecosystem generating reasons why they are smarter than science when this is brought up.
Let's investigate how little "evidence" they need before they completely ignore said research:
Many have the unmeasured, ridiculously unreliable anecdata "I produce amortized peak output working at a higher number of hours per week" (it's hard to tell that anyone has actually tried looking before claiming it, though: work 6 months at 40 hours/week and another 6 months at 70/hours a week). Why is this unreliable? Because working longer hours produces more artifacts of work, even when it produces less deliverable work. You have all these memories of being in an office, more emails, more comments in your bug trackers, etc. But how much work is done? Even if they did the experiment, there isn't a coherent way of measuring productivity of creative workers with n=1, almost all of us have quite a lot of variation in the complexity and familiarity of our work.
I know of only a couple people who have dramatically dropped their hours, and 100% of them are more productive (both more efficient and effective).
So there are people using almost no data (assuming they actually did measure themselves), and they claim to know better.
This is all to say, the startup ecosystem isn't thinking this through carefully. To the extent they end up being correct it will be largely coincidence.
So there are people using almost no data (assuming they actually did measure themselves), and they claim to know better.
Software programmers also frequently argue that it's impossible to measure software productivity.
Conventional wisdom, and many studies, hold that 40 hours of work per week are the optimum before exhaustion starts dragging your productivity down too much to be worth it. I read elsewhere that the optimum is even lower for creative work, namely 35 hours per week, though the sources I found don't all seem to agree.
In contrast, many tech companies in silicon valley demand (or 'encourage', which is the same thing in practice) much higher work times. 70 or 80 hours per week are sometimes treated as normal.
How can this be?
Are these companies simply wrong and are actually hurting themselves by overextending their human resources? Or does the 40-hour week have exceptions?
How high is the variance in how much time people can work? If only outliers are hired by such companies, that would explain the discrepancy. Another possibility is that this 40 hour limit simply does not apply if you are really into your work and 'in the flow'. However, as far as I understand it, the problem is a question of concentration, not motivation, so that doesn't make sense.
There are many articles on the internet arguing for both sides, but I find it hard to find ones that actually address these questions instead of just parroting the same generalized responses every time: Proponents of the 40 hour week cite studies that do not consider special cases, only averages (at least as far as I could find). Proponents of the 80 hour week claim that low work weeks are only for wage slaves without motivation, which reeks of bias and completely ignores that one's own subjective estimate of one's performance is not necessarily representative of one's actual performance.
Do you know of any studies that address these issues?