<i>One way to understand these trends, Aboulafia told me, is through the industry’s most beloved metric: the seat mile. If a plane with 300 available seats flies 1,000 miles, that flight clocks up 300,000 seat miles. Airlines are constantly comparing revenue per available seat mile, or Rasm, with cost per available seat mile, or Casm. Aboulafia, pronouncing these terms as “razzum” and “cazzum”, said: “As long as razzum is a nose above cazzum, you’re happy.”</i><p>If you're an Italian speaker, this can be very funny and ironic.