Hello, ThinkBlue, we meet again 
Starting with Caplan’s essay: http://econfaculty.gmu.edu/bcaplan/whyaust.htm
Rothbard’s rejection of the utility function approach led him to make strange ad hoc concessions to it elsewhere in his writings. Using his value scale approach, Rothbard was able to derive the laws of demand and supply as theorems.[11] But then inexplicably in his later discussion of labor and land, Rothbard conceded the theoretical possibility of “backward” bending supply curves.[12]
Then Block’s reply: http://mises.org/journals/qjae/pdf/qjae2_4_2.pdf
This criticism, too, misses its mark. Of course, downward sloping demand and
upward sloping supply are exceptionless propositions, given the ceteris paribus
assumption of no income changes. And, obviously, when this assumption is
relaxed, as in the case of the backward bending supply curve (or the Giffen good),
and income changes are allowed into the analysis, then it is theoretically possible
for such exceptions to occur. But why should neoclassical economics be granted a
monopoly position regarding this rather basic “insight”? Surely, the Austrians, too,
without any by your leave tugging at the forelock, may take note of the fact that
when price changes, income, too, can be impacted.
Then Hulsman’s reply, which IMO, is ridiculou, as he states that the shape of supply curves have nothing to do with price formation: http://mises.org/journals/qjae/pdf/qjae2_4_1.pdf
There are probably few Austrian economists who would claim that nothing of
value could be learned extra muros. However, Caplan’s conclusion is premature.
The fact that Rothbard occasionally refers to income and substitution effects does
not warrant the claim that these effects correspond to anything real. And it does
not make the Austrian theory of the price formation of land and labor dependent
on neoclassical insights. We have already pointed out that Mises did not bother
about the shape of supply curves or the underlying motivations of market participants.
His price theory stresses a much more fundamental feature of price
formation, for example, that all exchanges are (at least ex ante) beneficial for both
parties and that entrepreneurs appraise factors of production in terms of their
expected relative contribution to the monetary income generated by the production
process. It follows that consumers steer the allocation of resources in a market
economy. Nothing of this depends on the shape of supply curves, or on the
existence of income and substitution effects.
Then there is Caplan’s reply to both of them: http://mises.org/journals/qjae/pdf/qjae4_2_6.pdf
Caplan (1999) maintains that Rothbard contradicts himself by introducing
income effects and backward-bending supply curves after purporting to
prove that the laws of supply and demand are exceptionless theorems. Block
denies the charge; Rothbard is perfectly correct, given the “ceteris paribus
assumption of no income changes” (1999, p. 29). There is a fundamental
problem with Block’s reply, though. It hardly makes sense to invoke an “all
else equal” condition in cases where all else is of necessity never equal ! The
key neoclassical insight is that price changes ipso facto change income.
Income effects do not happen at the same time as price changes by miraculous
coincidence. They are inherent in the nature of price changes. Block’s
defense of Rothbard makes about as much sense as a “theorem” that “no one
ever dies of starvation,” which is apodictically true “given the ceteris paribus
assumption that no food is nourishing.”
Hülsmann, in contrast, amazingly declines to either (a) defend Rothbard’s
use of income and substitution effects, or (b) argue that this was an unfortunate
neoclassical corruption of Rothbard’s thinking. Instead, he remarks only
that “Mises did not bother about the shape of supply curves” and that relatively
little depends on this.18 Bear in mind that “shape” here is not just slope, but
sign! “The fact that Rothbard occasionally refers to income and substitution
effects does not warrant the claim that these effects correspond to anything
real” (Hülsmann 1999, p. 11). True enough; but Rothbard did claim to have
strictly deduced the conclusions that supply slopes up and demand slopes
down from the axiom of action. Why doesn’t Hülsmann say that Rothbard’s
supposed proofs warrant the rejection of the income and substitution effects?
If he thought Rothbard’s proofs were valid, he would. And if Rothbard’s proofs
of the laws of supply and demand are not valid, the remaining ten chapters of
Man, Economy, and State—everything from interest-rate determination to monetary
economics to the theory of price controls—rest upon error. If these are not
“fundamental feature[s] of price formation” (Hülsmann 1999, p. 11), what is?
Subsequent replies to Caplan deal exclusively with Probability (links can be found here: http://mises.stackexchange.com/questions/134/whats-the-best-austrian-response-to-bryan-caplans-essay). Block says he replied to the rest of Caplan’s article in an unpublished manuscript, but I cannot find that.