[ashr]

I don't believe 2.5 hours is representative, so please cite these studies. Personally,senior engineers (individual contributors) that I have worked with spend 4-6 hours per day making significant contributions on their own and the other 4-2 hours working/coordinating with their team and sister teams. The only plausible scenario where one can do an acceptable job in 2.5 hours per day is where a senior person is doing the job of an entry level person. For people managers, having effective 2-4 hour days on an ongoing basis are very unlikely in my experience. I am open to be surprised with examples that prove otherwise.

[cercatrova]

Here is the study I read it from, there might be others. In my experience, yes, it doesn't work for managers, only those who are individual contributors doing programming full time. I doubt however that even the senior managers are coding the entire time for 4 to 6 hours, it is difficult to do so every single day. More likely, you perceive them to be doing that much work since they are present during that time, which is the same reaction I get as well; colleagues and bosses speak of how much work I get done compared to others, yet they don't realize I work a lot fewer hours. It's all about efficiency.

https://www.inc.com/melanie-curtin/in-an-8-hour-day-the-aver...

[yoloswagins]

A specific note about this quote:

> However, this eight-hour movement didn't become standard until nearly a century later, when, in 1914, Ford Motor Company astonished everyone by cutting daily hours down to eight while simultaneously doubling wages. The result? Increased productivity.

What happened was the shift from craftsmen at a workbench to a deskilled assembly line had significant turnover. The cost of training and retention was high enough that Ford instituted the lower working hours and higher wages.

From one of Ford's biographers: “So great was labor’s distaste for the new machine system that toward the close of 1913 every time the company wanted to add 100 men to its factory personnel, it was necessary to hire 963.”

You see this in shipyards during the war war 2 years where once the initial pool of workers is burned out, you need to raise wages to bring in more workers.

[yoloswagins]

The classic study on this topic that everyone loves to cite is "“Constant, Constant, Multi-tasking Craziness”: Managing Multiple Working Spheres", from 2004, where anthropologists observed 14 workers building software, specifically: * Four software engineers * Six analysts (more like a Project Manager) * Four managers (like an Engineering Lead)

What they found is in a ~nine hour day, the people did between ninety minutes to 4 and a half hours a day doing their 'focused work'. You can imagine that project managers are pushing 90 minutes, and the engineers are closer to 5 hours.

All of this is on top of two hours a day chatting with people across cubical walls.

In reading a bunch of these studies, you find small populations, and a focus on law firms and consulting because their work is significantly more legible.

[srtjstjsj]

Non focused work is still work.