very interesting article. But to get a thorough answer, you would have to analyse the way the society was at that period and the way it is today. See how the kids are today. In front of PCs all the time.. often playing video games all the time.. all these stuffs would have to be touched and you would have a nice (not so nice) picture illustrating the answer to your question.
I look at the times of past races the club has run in the 90s Wow. The first 20 times were in the low to mid 5s for a small race. These days there is just about 5 per race. But these are local races with only 250 to 350 runners.
I would like to note, We do run in team points races in New York. And the first 10 to 15 runners are under 5 min per mile pace on a fair 10k. The first three places are under 4:45 pace. So great runners are around. Its just more of us non flash Gordens are running these days.
Thanks for response! I have received some interesting comments on my blog page from a running magazine editor, tv commentator and nationally known running coach. Feel free to add your comments there as well!