There was a time at the University of Chicago when investment in human capital was viewed as a "good thing". Robert Lucas wrote down models where it was the key to long run economic growth. Gary Becker, Sherwin Rosen, and Jim Heckman wrote down micro models of optimal investment in such capital. In these models, there were no "negative externalities" associated with human capital investment. But now fast forward to 2017 and I see that the new University of Chicago's scholars worry about the "downside" of family human capital investment.
The Harris School Prof appears to be telling a story that there is "too much" parenting as parents compete for scarce elite slots at Ivy League schools and Wall Street.
Does the inelastic supply curve really determine the payoff of investment in human capital? Why can't the supply curve of slots become more elastic over time? For on this point, read my blog post from August 2014 here.