Well, since I'm making ready for the day unusually quickly this Saturday morning, I think I'll take the time to properly explain my deep disagreements with your position.

* Markets cannot be claimed to "beat" Arrow's Impossibility Theorem any better than any other method of preference aggregation.

* Economics does not derive from foundations for ethics, nor form a foundation for ethics, nor say anything about ethics or meta-ethics. Value-neutrality is basically the whole point of economics, ever since Adam Smith codified the subject.

* In fact, to drive home that second point there, if two people agree on a preference ordering, it doesn't matter whether that ordering has any metaphysical or "foundational" significance whatsoever. Economics is making a weird assumption, from the anthropological point of view, that people won't agree on preference orderings -- what with all being humans and thus having very similar material needs.

* In further fact, "free market" systems, taken as foundations for morality and society, give rise to their own "paradoxes" (https://en.wikipedia.org/wiki/Liberal_paradox).

To unpack the first point, which is most likely the important one... The Impossibility Theorem says that no system of ordinally-ranked voting (in which candidates are listed in order of preference) can satisfy the following three criteria, and also something called Pareto efficiency we'll get back to later.

The three criteria:

* If every voter prefers alternative X over alternative Y, then the group prefers X over Y.

* If every voter's preference between X and Y remains unchanged, then the group's preference between X and Y will also remain unchanged (even if voters' preferences between other pairs like X and Z, Y and Z, or Z and W change).

* There is no "dictator": no single voter possesses the power to always determine the group's preference. Note that "dictator" here is a technical term: the hypothetical "dictator" would probably not know who he or she is. An informal term that captures the correct meaning in today's term would be closer to "swing voter" -- Asimov wrote a short story about the phenomenon (http://www.5novels.net/ScienceFiction/Asimov41/27325.html).

So, how does a "market system" do "better" than a centrally-planned one? Well, firstly, it employs cardinal (real-number) preferences rather than orderings, and secondly, it allows for dictatorship (primarily of the wealthy, and in both the technical and informal senses). This of course means that any preference-aggregation system which is willing to bite these two bullets (preferences are numbers rather than orderings, and there may be one person in the population whose voice determines the outcome) faces no troubles from Arrow's Theorem. The Gibbard-Satterthwaite Theorem will still apply (any system must exclude some candidate, suffer from a potential (if unknown) dictator, or be vulnerable to tactical voting), but it of course applies to "market planning" just as much as to any other system (particularly since market planning bites the dictatorship bullet).

As to the question of efficiency, capitalism does not even claim to provide social efficiency in any sense, merely Pareto efficiency regarding things which can be owned as property. Pareto efficiency just means, "The best outcome that can be obtained without taking from the rich to give to the poor." Worse, markets are not known to converge to equilibria in real life -- they're far too stochastic for that.

And then of course we run into all the previously-mentioned issues of trying to combine freshman political science, wildly idealized economics, and right-wing ideology to claim to have formed a foundation for morality or to answer fundamentally moral questions.