Utilitarianism and Trade
The debate between "PCR" (Paul Craig Roberts) and others underscores the fatal problem among libertarians of relying too heavily on Utilitarian arguments. Outside of the fatal problem of relying too heavily on Utilitarianism, there is also the strategical problem. As Rothbard once said, "the young kids out there are not going to be willing to go to the barricades in defense of lowered transaction costs!" While Utilitarian arguments -- along any other arguments for Libertarianism, such as Christian arguments -- are always useful, I believe the core argument for libertarianism should be based on the non-aggression axiom, thus Natural Rights.
What is often overlooked by many is that simply because someone is an Austrian economist -- that is, knows of the Utilitarian consequences of intervening in the free market -- does not mean that they will also necessarily be a Classical Liberal (as was Mises), a libertarian, or an anarcho-capitalist (as was Rothbard). Austrian economics, more generally speaking Austrian praxeology, deals with economics and praxeological factsj; e.g., enforcing a minimum wage illegalizes jobs. It does not say anything about morality -- in other words, it does not tell us anything about right and wrong; e.g., it does not say "enforcing a minimum wage is wrong." For the analysis of right and wrong, we need a moral framework. I believe Rothbard once said something along the lines of, "Bankers know nothing about how the banking system works. Either that or, of course, they are totally evil."
Utilitarian justifications of libertarianism -- relying on moral Utiltarianism -- are for similar reasons problematic. What of when allowing individuals to act freely does not result in the best utilitarian outcome (if such a situation ever does happen, which I remain convinced it does not)? In such a case, should we then abandon libertarianism, and bring in The State? I argue that, no, we should not. We should support free trade because it is a voluntary transaction between two individuals acting of their own free will, who are not violating the non-aggression axiom by engage in it.