When 10% is not equal to 10%
I saw a story go by a few months ago. It was something or other by a college professor which basically amounted to "kids these days". His assertion was that he had been doing this for 30 years, and now he has entire classes of incapable students rolling through. It wasn't like this before.
You can see this in other fields, too. There's this repeated assertion that everything is going to hell with all of these new people. The old ones were so much better. Pointing out that "kids these days" is a lamentation that goes back thousands of years doesn't help with some people. I'm beginning to think they need a more numerical approach.
Let's make up a percentage, and say that 10% of all students are going to be incapable of grasping whatever that professor is trying to teach. In year 1, 100 students go to college and cross his path, and so he encounters 10 "bad ones". 10 isn't so bad.
Now, time passes, and it's year 30. The population has grown and the school has grown with it. Also, more people are going to college. 1000 students attend this year, and 10% of them still can't hack it as far as our prof is concerned. Trouble is, this time, that means 100 students, and now it looks like an epidemic.
Think about what 10 people looks like. 10 people going to lunch is a little big but you can make it work. Now imagine what 100 people looks like. You're going to fill up most of the restaurant just with that group.
Both of them are 10% of their respective populations, but whereas 10 subpar students is "meh" territory, 100 becomes the justification for screaming "the sky is falling" and writing treatises about how bad things have gotten.
As long as the people who are complaining are talking about raw numbers and not percentages or ratios, there's no way to be sure what's really going on. Actually calculating those percentages would require at least basic awareness of the bigger picture, so by asking for it, the greater truths might be revealed.
Ultimately, I think this all comes down to matters of human perception. Things which may be the same proportions may look completely different when expressed in terms of actual quantities, particularly when we're talking about unique things like individuals.
Show me data that proves the percentages are changing. Then maybe I'll flip out, too. Until then, I'm just going to shrug and focus on something else.