Commercial airlines overbook flights, selling more tickets than they have seats, because
a sizeable number of reservation holders don’t show up in
time for their flights. But sometimes, there are more passengers
wishing to board than there are seats. Most airlines
try to entice travelers to voluntarily give up their seats in
return for free travel or other awards, but they do have to
“bump” some travelers involuntarily. Of course, they don’t
like to offend passengers by bumping, so they are constantly
trying to improve their systems for predicting how
many passengers will show up. Have the rates of “bumping”
changed? Here are data on the number of passengers
involuntarily denied boarding (“bumping” is not the approved
term) per 10,000 passengers during the periods of
January to September in 2016 and 2017 by airline.