Okay, here's the reply regarding the second subject, coordinated airline fares:

Actually, in a pure economy, with complete information available to all consumers, and a fungible or homogenous commodity, you would expect to see all sellers selling at exactly the same price. A perfect example used in economics and antitrust classes is grain, milk or concrete by the ton.
Given perfect price information, consumers will never pay a higher price for the same commodity. Thus, at a highway intersection, four gas stations will eventually gravitate toward the same price because 1) the price is posted on big signs, so all consumers have perfect price information, 2) gasoline is, for most purposes, the same commodity, and 3) the cost of going to any of the three is approximately the same. To the extent that they can price differentiate, it is because they may offer different services, or because their advertising has convinced consumers that their gasoline is somehow different--brand differentiation.
Where does that take us to with airlines. Airline seats are, at their basics, transportation between point A and point B. the competitors have perfect information about each other, because they have the ability to monitor the reservation systems to see what each is charging. So, you would expect prices to be the same.
However, they have been caught trying to coordinate prices changes with each other. A few years ago, the airlines were found to be involved in "price signaling" through the fare reservation systems (Sabre, etc.). Basically, the airlines were signalling intended price moves, by putting into the system price changes with future effective dates, to see whether the others would agree to it. It was actually a very public version of the airlines sitting around a room saying to each other, "okay, I think we ought to raise prices on these routes 10%, what do you think?" "No, I think I will agree to 5%"---without having to be in a room together doing it.
As I understand it, the consent decree that came out of that case prevents the airlines from doing that type of price signalling in the future.