A FIFO queue is essentially like an auction where you use your wait time in order to bid for service -- the highest bidder (longest waiter) wins.  LIFO service as proposed here is equivalent to the <i>lowest</i> bidder winning instead, meaning everyone will try to bid zero (or as low as they can).<p>This changes if you have some uncertainty in the cutoff time -- in the flight example, attendants would close off the gate at some randomly determined time, and latecomers would be able to get great seats -- but they&#x27;d also have an excellent chance of missing the flight entirely!<p>In this case, the thing you&#x27;re bidding with is how much you&#x27;re willing to risk missing the flight.  If you know that the flight will close at a time uniformly distributed between 10:00 and 10:30 for example, those who arrive at 10:29 are willing to accept a 29&#x2F;30 risk of missing the flight in exchange for being virtually guaranteed their choice of seats.