Brink Lindsey sent me a draft of his just-released Human Capitalism (now available for purchase) back in February.  Here’s what I told him then, reprinted with his permission.  From what I understand, Brink took some of my suggestions to heart, so these criticisms may not apply to the final version.

Then again, they may. 🙂

Hey Brink, finished your book.  Overall, you’ve got lots of good
material, but the ending needs to be stronger.  Detailed comments:

1. (chap 2) On premodern mortality: Robin Hanson keeps telling me that
pre-farming violence was actually low.  I’m skeptical, but if I were
writing a book I’d want to follow through on this claim.

2. (chap 3) Is it really only recently that human capital became 70% of
all capital?  I’ve often heard that 70% of income has been going to
labor for a long time.  Not true?

3. (chap 3) Heckman’s claims on the GED have been challenged.  This
paper is very careful:

4. (chap 4) “People raised in the upper-middle class are far more likely
to stay there than move down…”  Unless you’re using non-standard
definitions, this can’t be right.  If the upper middle class is above
the mean, then mean-regression guarantees that its members tend to move

5. (chap 5) You’re misstating Charles Murray.  Murray is careful not to
base his argue on the genetic origins of IQ differences; his point is
that *whatever their cause* IQ differences are very hard to change.

6. (chap 5) One of the biggest flaws in your story: you’re not
addressing the broader literature on the heritability of income.  Yes,
as Bowles and Gintis show, the heritability of IQ can only account for a
small fraction of the inter-generational income correlation.  But there
are *many* hereditary traits that could affect income; IQ is just the
tip of the iceberg.  And twin and adoption evidence on the heritability
of income shows that – whatever these traits might be – heredity
accounts for virtually ALL of the inter-generational income correlation.
 See the section on “Success” in my kids book – especially all the
citations, which were very complete c.2010.  (You should also discuss
twin evidence, not just adoption evidence).

Take self-discipline.  You’re right to mention it.  It’s important.  But
it’s also hereditary!  Indeed, heredity accounts for roughly 100% of the
(modest) family resemblance we see.  This is straight out of mainstream
personality psych textbooks and lit reviews; see the section on
“Character” in my kids book.  The heritability of self-discipline
doesn’t mean self-discipline can’t be changed; there’s also a big role
for non-shared family environment (the residual).  But heritability
estimates for self-discipline do mean that existing differences in
upbringing have little effect on adult self-discipline.

3. (chap 5) You correctly note that studies of kids’ IQ find higher
effects of upbringing than studies of adult IQ.  This is true for almost
every trait: The short-run effect of parenting is larger than the
long-run effect.  But then you cite the French adoption studies, which
as far as I know are ALL studies of kids.  How do these in any way
undermine the standard behavioral genetic view: Upbringing matters in
the short-run for IQ, but not in the long-run?

The studies about how many words kids hear are at best another example
of the *short-run* effect of parenting on IQ.

4. (chap 5) Who are the “genetic determinists” you’re attacking?  Every
serious behavioral geneticist will happily tell you that since identical
twin correlations are less than 1, genetic determinism is demonstrably
false.  What you’re really arguing against is what I call “parental
irrelevantism,” which does indeed have many well-published proponents:

5. (chap 6) If the relative supply of college graduates is rising by 2%,
how can you call that “stagnation” of human capital development?  This
is analogous to Tyler’s claims about “stagnating” growth that you
rightly criticized.

6. (chap 6) Even if the French adoption studies you cite reveal a large
effect of working- versus middle-class parenting, adoption evidence
still strongly undermines the view that parenting style matters much
*within* the middle-class range.  But you seem to believe that elite
parents’ “relentless” approach is having big long-run effects.  Why?
Readers need to hear that helicopter parenting is *not* the source of

7. (chap 6) There may be “no prospect for a return to the more
authoritarian morality of yesteryear.”  But what about a marginal move
in that direction?  And if the breakdown is indeed caused by the absence
of material scarcity, wouldn’t drastic cuts in the welfare state –
drastic enough to restore labor force drop-outs and unskilled single
moms to material scarcity – revive the morality of yesteryear?  Why
doesn’t this lead to the very unliberaltarian view that the welfare
state is the problem?

8. (chap 7) Talk about “reshaping the environment in which most
Americans are born and raised” may sound creepy and totalitarian even to
the typical statist.

9. (chap 7) You should talk a lot more about vocational education.  If
the problem is our dysfunctional working class, why not focus on
countries where the working class is employed and disciplined – and how
these countries make it happen?

10. (chap 7) The section on early childhood intervention is weak.  You
know the evidence is very mixed.  So why do you embrace this approach
anyway?  Because it sounds good?

11. (chap 7) Your case against tuition subsidies really comes out of
nowhere.  Almost everyone will think that it contradicts your previous
embrace of Goldin-Katz, etc.  At minimum, you should delve into the
literature on the varying benefits of college by major, quality, student
ability, etc. to cement your case.  Of course, if you want to appeal to
the signaling model, great!

12. (chap 7) If “progress will inevitably be halting and partial,”
shouldn’t you try harder to lower readers’ expectations earlier in the
book?  Maybe even consider the possibility that we should just learn to
live with rising inequality?

One last comment that probably won’t be very helpful, but I want to get
it off my chest: When I see the hard work and positive attitude of the
typical immigrant, I find it very hard to sympathize with the problems
of the American working class.  The so-called American poor are born
with so many advantages, but they squander them through their own bad
attitude and irresponsible behavior.  Yes, in a welfare state the
problems of my country’s working class are my problem.  But that makes
me want to *attack* the welfare state, not expand it to help undeserving
Americans even more.  The people we should be worrying about are
immigrants and would-be immigrants who can’t even legally accept a job
offer, not Americans who can’t bother showing up to work on time.

Keep in touch, Brink.