When I was in high school, I wrote quite a few letters to my local newspapers.  The Daily News published a few, but I don’t think I ever cracked the Los Angles Times.  Until yesterday.  Highlight from my piece in the Opinion column:

Almost everyone pays lip service to the glories of education, but
actions speak louder than words. Ponder this: If a student wants to
study at Princeton, he doesn’t really need to apply or pay tuition. He
can simply show up and start taking classes. As a professor, I assure
you that we make near-zero effort to stop unofficial education; indeed,
the rare, earnestly curious student touches our hearts. At the end of
four years at Princeton, though, the guerrilla student would lack one
precious thing: a diploma. The fact that almost no one tries this route —
saving hundreds of thousands of dollars along the way — is a strong
sign that students understand the value of certification over actual

Read the whole thing.

P.S. As you may know, op-ed authors don’t choose their titles (or subtitles).  “School is all about signaling, not skill-building,” is an obvious overstatement.  My real view, as I state in the article, the book, and many other places, is that school is mostly signaling.  My preferred point estimate is 80% signaling, but I’m not married to that number.