Over at Leeham News where is a heated debate (once more) over if the A320(neo) or the B737(MAX) is the more efficient aircraft. As both aircraft were ordered and are flown in thousands both aircraft obviously cater their respective users - besides there are quite a few airlines operating both aircraft.
I tried to lay out how looking at DOC's or COC's or looking at costs per flight or per seat influences such a comparison in an earlier post.
Let's have another look at it. DOC or Direct Operating Costs are comprised of