It is better to run 16:xx on 25-40 MPW, than 15:xx on 75-100 MPW

Nope, 15 is better than 16.

False. It's always better to run 15:xx than 16:xx

Just run 1hour a day, 6 days per week.

it is better for most people.

better yet, 17:xx on 15-20 miles per week.

or 18:xx on 5-15 miles per week.

100%. You have found the sweet spot.

I assume you mean that the seconds which would substitute "XX" would be the same, or nearly the same, for both possibilities...so a full minute difference, more or less

I've asked myself a version of this. since you talked about a family and a job, I assume you're out of college (if it were college, the answer would definitely be 15:xx). if you're out of college and are pretty sure you can't get PRs anymore, then almost definitely 16:xx. although if you think you can still get a PR and you're motivated/have a lot of free time (basically, if you're 23-25), then go for the 15:xx at least for a bit. I guess in the out of college scenario, just do what you like? maybe the answer is somewhere in between even those two (as it is for me): 50-60mpw, halfway between 15:xx and 16:xx

Why are you ignoring the wide range between 40 and 75? A lot of people can run their best in that 50-70 miles/week range. That's like an hour a day which isn't unreasonable at all for exercise.

By that logic, its even better to run 24 minutes on 10 miles a week

Think how much time you'd have for those other things if you didn't run at all.

I wish it was considered doing to run for more than an hour a day. That would make running more available to people and talent have more to say than luck

50 mpw is enough to run 15:00 with proper training and not that much talent.

Cope

you need to be more specific. there is a huge difference between 15:00 and 16:59. there is also a huge difference between 25mpw and 40mpw

You people are such freaks. The average adult man is not running under 17 minutes in the 5k on 40mpw. The average highschool xc program that runs 40mpw has 1-3 genetically gifted kids who have been athletes their entire lives who run in the low 17s.

How are you only getting a minute out of tripling your mileage

Is it better to run 36:xx on 0MPW than 16:xx on 35-40MPW?

I have more time for other hobbies and pursuits.
More time for family.
It prevents boredom, burnout and fatigue.
It reduces cumulative wear and tear.

Your answer was in your question.

More time for family and hobbies. In the grand scheme of things (unless you are a high school runner), 15 and 16 aren't much different. And if spending the time training isn't a reward in itself, the answer is pretty clear.

Bad training or just horribly low potential. Some people won't run sub 15 no matter what they do.