Beware of the selection bias: even if veterans show more productivity, it could just be because the military training has selected those with higher discipline
Data from periods of forced conscription would correct for that bias, but would introduce the new bias of a 4-F control group. Is there a fancy statistical trick to combine the data and eliminate both biases?
Draft lotteries provide randomized experiments. The most famous one is the Vietnam draft analysis by Angrist 1990 where he finds a 15% penalty to lifetime income caused by being drafted. There's also little evidence of any benefit in Low-Aptitude Men In The Military: Who Profits, Who Pays?, Laurence & Ramberger 1991, which covers Project 100,000 among others, which drafted individuals who would not otherwise have been drafted either as a matter of policy or, in the ASVAB Misnorming, unrealized accident. (As Fredrik deBoer likes to say, if there's any way it can possibly be a selection effect, then yeah, it's a selection effect.)
This suggests we might look at data from countries like Israel and Singapore with mandatory military service (although it's complicated because I think both have alternative civil service for objectors and exceptions for certain groups), and look at how results of veterans there compare with similar populations to hold other cultural effects on discipline constant.
I am a veteran, and my inside view suggests two things: one, the least disciplined members of the population are filtered out by the military (which is to say they are not accepted or kicked out early); two, the military experience pushes veterans towards the extremes.
Reasons to consider that veterans would be more productive than average:
Reasons to consider that veterans would be less productive than average:
My expectation is that the productivity advantage is highest when veterans enter a civilian industry that matches military tasks closely, like compliance with regulations or uncomfortable work environments. I also expect that the veterans who fail to re-adapt to civilian life suffer an almost complete collapse of productivity.
Turning to the question of discipline, I think we will benefit from a little context. Discipline in the military is very much a team phenomenon; Army training is focused overwhelmingly on establishing and maintaining a group identity. Most of the things people associate with military discipline require other people to make sense, like the chain of command, pulling security, and how tasks are divided. Even the individual things like physical fitness or memorizing trivia, are thoroughly steeped in the team environment because they are motivated by being able to help your buddy out and are how status is sorted in the group.
I believe your friend's statement:
If you can just train yourself like you're in the army, then you can become just as self disciplined as a soldier
is wrong as a consequence, because you can never train yourself like you are in the Army. That fundamentally needs a group, entirely separate from the question of social incentives and environment. Outside of the group context, discipline doesn't really mean anything more than habit formation.
is wrong as a consequence, because you can never train yourself like you are in the Army. That fundamentally needs a group, entirely separate from the question of social incentives and environment.
How is a group separate from the question of social incentives and environment? Having a group of people to motivate you seems like intrinsically a question of social incentives and environments.
I took my friend's suggestion to be less that we can actually gather the resources to train ourselves like we are in the military, and more that if we were to do so, it would improve our discipline in the long-run. Hence the popular wisdom (or misconception) that military "straightens people out."
My understanding is that there are a bunch of charitable efforts to try to convince employers to hire veterans, and that it's illegal in the US to discriminate against veterans in employment. If military veterans were actually more productive, I don't think these charities or anti-discrimination laws would exist.
I'm not sure that follows. For many jobs, we know that people in their mid 30s are generally more productive than people who are in early career, for example. But there are still anti-discrimination laws against not hiring old people. Point being that while some of X might be good, too much of X could be bad. This could tie into Ryan's point above that while there could be some average productivity benefits, for exceptional cases,
I expect that the veterans who fail to re-adapt to civilian life suffer an almost complete collapse of productivity.
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How are you defining productivity? In my experience veterans do have a vastly greater capacity for buckling down and grinding through, in a way that people who have not had military service do not. However, on the flip side, I've also seen the failure mode where veterans assume that buckling down and grinding through is the only way to solve a problem, rather than stepping back and considering the broader picture. From what I've seen, it takes some time for veterans to realize that, in the civilian world, orders aren't absolute, and that if something doesn't make sense, you have an obligation to question it, rather than to just grind out the work.
In the military, there are strictly prescribed procedures for how certain things should be done, and deviation from those rules is punished. In the civilian world, not only is deviation not punished, but it can even be rewarded, if you find a more efficient way of accomplishing the task.
Therefore, while I agree with your friend that veterans have greater self-discipline, I disagree with the assertion that this would lead to greater productivity. It's plausible to me that the improvement in self-discipline is more than canceled out by the increased fixation on following rules and procedures unquestioningly.
Is lack of discipline a big problem at an average workplace? I would expect most offices to provide sufficiently good social incentives that most people spend most of their time working, in which case any productivity-boon from increased discipline would be swamped by other (selection) effects from military training.
Increased discipline could translate to notably higher productivity for undergrads, PhD students, or people who work from home, though. My impression is that such people struggle much more with procrastination.
Relatedly, China seems to be doing their best to teach discipline in schools, so you could look at whether that seems to be working. This is obviously mixed in with lots of ongoing social incentives, though. Relevant ssc: https://slatestarcodex.com/2020/01/22/book-review-review-little-soldiers/
I was having an argument with a friend the other day. It went vaguely like this,
Friend: "I'm not very disciplined. At some point I'm going to buckle down and train myself to be much more disciplined."
Me: "From experience and from what I know about humans, that's not going to work."
Friend: "Why? Motivation can come from within. If you can just train yourself like you're in the army, then you can become just as self disciplined as a soldier."
Me: "Yes, but the reason why people in the military are disciplined is because they have social incentives to be. In order to become disciplined, you need to create an environment for yourself that shapes your motivation. You can't just wake up one day and become a soldier."
Friend: "Sure, you might have to set up some environment like that. But once you've trained yourself, the discipline will stick, and you will be able to self motivate yourself from then on."
Me: "This theory would predict that people who were trained in the military would be much more productive three years after their service, compared to people who were never trained in the military. Do you agree?"
Friend: "Yes, I think that is likely."
Me: "I disagree. They might be slightly more productive but I'd predict it would be pretty similar."
So who is right?
I haven't been able to find direct research, but this seems like a classic instance where a debate can be settled by simply referencing a high quality experiment.