I don't believe either of those are true. As it happens, the largest companies capture so much of the market that they can afford being inefficient, and they st

I don't believe either of those are true. As it happens, the largest companies capture so much of the market that they can afford being inefficient, and they still have the power to push the competition into a corner. There are small-margin markets where this doesn't happen, bit then those markets don't have huge companies either.