I'm curious why you made that a "We economists" statement, but if you were one your instinct should have associated ag's comment to a social choice problem. (Not that his response wasn't a painfully theorist one)
Is communism a legitimate economic discipline? The answer is "no", and that's why I responded with moral theory, instead.
I'm not a teacher so I have no interest in humoring theories that have virtually no merit.
I'm not communist by any means, but to say it isn't a legitimate economic discipline is both ridiculous and inane.