(Posted: February 19, 2009) As soon as I saw the title I knew the answer ... economics. The vast majority of people buy the cheapest flights they can, and wit

(Posted: February 19, 2009) As soon as I saw the title I knew the answer ... economics. The vast majority of people buy the cheapest flights they can, and with modern jet engine technology it's cheaper to fly slightly slower. The same is true with ocean going cargo ships. They deliberately cruise[0] slower if they are under some nation's flags because the wages are lower for those nationals[1], and the balance between cost of wages versus cost of fuel shifts towards spending more time (higher wages) at a lower speed (less fuel). Roughly, steaming faster increases your fuel bill but lowers your wages bill, and vice versa. The exact balance point depends on the base rate for the wages of the crew. And the number of crew. The arithmetic is brutal, but unassailable. [0] The technical term is, believe it or not "steam" [1] It's complicated. Very complicated.