The eponymous genius is not me. (I wouldn't even know the word "eponymous" if I wasn't an REM fan.) It's my son.
I raked the back yard with the two boys this morning before heading off to teach. At the end of raking, Jerome said, "We didn't get all the leaves," and Joe said, "[Jerome], you couldn't get all the leaves unless you spent, like, 20 hours raking."
Yes, my seven-year-old understands diminishing marginal returns. Half of my upper-classman students don't get it. And more than half of America doesn't get it.
We got most of the leaves, but we didn't spend most of 20 hours raking. So why would we have to spend so much time to get our yard leaf-free? Joe understands that the first leaf raked is the easiest leaf to rake, and the last leaf to rake would be the hardest. After an hour we called it quits because the marginal benefit of raking had fallen below the marginal cost of the additional work.
What is my evidence that most Americans don't get this? The prevalence of "no child left behind" thinking. Honestly, some children should be left behind. The last kid to learn how to read--the one who just cannot learn how to read--is going to cost billions of dollars. Is it really worth that to us? Well, let's ask if it's really worth that to HIM. Who was the last person to spend billions to learn how to read? If no one makes such an effort for his own benefit, why should we collectively make such an effort for him?
I'm so happy that my son intuitively understands this. It's the best thing that's happened all day.