No one in the Cato Unbound exchange on Charles Murray’s education book responded to my closing questions.  I asked Murray:

In your view, why precisely does the market financially
reward students for taking lots of classes that at best seem distantly
related to job performance?  You don’t seem ready to sign on to my signaling story.  Do you have an alternative?  As I’ve said before, I agree with most of your conclusions.  It’s your model that leaves me wanting more.

I also asked Pedro Carneiro:

If you mentally review your years as a student, can you honestly say
that your typical class raised your marginal productivity?  If you
adjust for the fact that you’re an academic, doesn’t the weakness of
the connection between what you learned and what you do trouble you?

Does anyone want to trying channeling Murray and/or Carneiro?  I need closure!