why are there so few libertarian academic philosophers? And why do economists across the political spectrum have so much more appreciation for the benefits of markets than the general public, the typical college grad, or the typical philosopher for that matter?
Speaking as an undergraduate econ major/philosophy minor, I'd say that studying philosophy typically leads not to "willingness to grapple with ideas," but to blanket skepticism.
I am not making any sort of claim about academic philosophers. I really should not have tried to make a claim about what philosophy teaches. The claim I wish to make is one of selection bias. What sort of person does the philosophy major select?
I contend it selects someone with more of an interest in ideas for their own sake than the typical undergrad. I contend that it selects someone with a greater desire to put together a coherent world-view than the typical undergrad. I contend that it selects someone with a lower need for conformity, intellectually and otherwise, than the typical undergrad.
The result is that a philosophy major will be a "high-variance" intellect. While everyone else clusters around a mean that is a muddled mixture of folk Marxism, paternalism, environmentalism*, and a grudging tolerance for markets as a necessary evil, the philosophy major is more likely to stray from the consensus. The result may or not be libertarian--it could go in the other direction.
But my guess is that if you find a passionate defender of free markets, chances are you will find someone who at some point developed an interest in philosophy. I suspect that the typical econ major favors free trade more from a consensus-conformity perspective than from true conviction, and if the wind blows hard the other way, the econ major will readily sacrifice free trade principles.
*Bryan and I both attended this talk by Deidre N. McCloskey, at which she said in an aside that our schools today teach environmentalism as a more-or-less official religion, to fill the void left by secularism. The talk was mostly just a series of insightful asides.