> Business and 1st class make a lot of money for airlines. Not letting them board first (although personally I've always wondered why this is desirable) would d

> Business and 1st class make a lot of money for airlines. Not letting them board first (although personally I've always wondered why this is desirable) would devalue their tickets and make less profit for the airline. Seems like you can model this as equivalent to boarding two airplanes. Boarding first class is like boarding one airplane, and when you're done with that you start the clock ticking on boarding coach, which is like the second airplane. In which case, you have two airplane-boarding sub-problems, and the number you care about is the sum of the times. You can apply whatever strategy to both subproblems, then you can reduce both numbers that you're adding, and you still get a smaller sum. Maybe it's not as much of an efficiency gain as doing away with the first class and coach separation, but it should still be an efficiency gain.