I think most people can immediately identify with the idea of "working" 40 hours while really only doing 15 hours of hard work and 25 hours of paper pushing and procrastinating. Maybe not in your current job but almost certainly in some job you once held.
I think this is a product of work culture. There are, at almost every halfway useful company, a number of truly busy people. These people have 40 hours of things to do every week, or at least need 40 hours to properly instruct their subordinates. However it is often the case that they only really need 15h of hard work from each subordinate. The issue is that it's not culturally acceptable to say to your boss "I just did all you need from me this week in a few hours, I'm going to the beach now". So such a worker faces the choice of either speaking up and asking for more work, or dragging out the minimal work they have to do until it takes an "acceptable" amount of time. Since time is our most valuable asset the culture of a company is considered fair when people are giving relatively equal time sacrifices to the task at hand.
I know I have been lucky enough to have a manager that was not offended if I finished all of my work early and left, but 99% of people never have that luxury. It's psychological, most people don't want others to get off easy.
I think this reasoning doesnt depict the real model.
If you are supposed to do 15 hours of real work, the ambiance of leaving when you are done with it is in the best case, going to let you do those 15 hours, but worst case you wont even fullfill that.
An example of that is finishing up something, and then a bug pops out after someone checks it out. If you are not in the office, your work is incomplete.
For the value vs work proposition, its entirely inapplicable for everyday operations. Who is measuring the value? and how do you get to influence those decisions?
If you get to work a project brought down from the product manager, you implement it completely, and the project turns up to be a total bust, or just useless, or not used, you provided 0 value. Does that mean you have to work extra to make up for that?
Or you work a couple of hours rogue-like and discover a dev-ops inefficiency and you can cut down server costs 10%, saving the company 100ks of money. Does that mean you don't have to show up for work anymore?
So value is not the word at play here, its maybe the efficacy of going through your work load. The more time you spend commited the more you will do, and that is pretty strict. The guy doing 15 is not going to get more than his own version doing 40, no matter what.
It's something of an efficiency fallacy that keeping all resources (people and/or machines, etc) 100% occupied is the best way to get highest system productivity. Unfortunately, the assumption is baked-in to a lot of our work culture.
Regarding people, good reading in this concept is Goldratt's, "The Goal"[1]. There are more technical approaches of the concept. But, the novel is great in terms of getting a visceral feel of why there are busy resources, but at the same time you need idle resources within the same pipeline for good system performance.
I don't think most people make the conscious choice to drag out their work, it just happens naturally as our work expands to fill the time we've committed to being in the office.
The book Peopleware condemns Parkinsons Law as unproven.
The problem with Parkinson's Law is that management also knows it, so they think they can constrict their deadlines a lot and the work will get done, and if its not, they can pressure you to work extra hours to do it.
I've heard about almost this exact situation. A brilliant developer I knew when I worked for a Smalltalk vendor (one who made a seminal contribution to his programming community that went on to influence almost every other programming community) was working as a contractor for a telecom. He found that he could get all of his assignments for the week done in 1 or 2 days. Basically, his manager told him to do more work each week, so that the suffering would be distributed evenly.
> I know I have been lucky enough to have a manager that was not offended if I finished all of my work early and left
A problem with most knowledge-domain jobs is that the work is never done.
There are always new tasks incoming and other tasks parked pending further information, so there's no opportunity for for employees to say 'I'm finished'.
In that scenario the only way the employee can escape is to say 'I have met my assigned hours'.
I think most people can immediately identify with the idea of "working" 40 hours while really only doing 15 hours of hard work and 25 hours of paper pushing and procrastinating. Maybe not in your current job but almost certainly in some job you once held.
I think this is a product of work culture. There are, at almost every halfway useful company, a number of truly busy people. These people have 40 hours of things to do every week, or at least need 40 hours to properly instruct their subordinates. However it is often the case that they only really need 15h of hard work from each subordinate. The issue is that it's not culturally acceptable to say to your boss "I just did all you need from me this week in a few hours, I'm going to the beach now". So such a worker faces the choice of either speaking up and asking for more work, or dragging out the minimal work they have to do until it takes an "acceptable" amount of time. Since time is our most valuable asset the culture of a company is considered fair when people are giving relatively equal time sacrifices to the task at hand.
I know I have been lucky enough to have a manager that was not offended if I finished all of my work early and left, but 99% of people never have that luxury. It's psychological, most people don't want others to get off easy.