=+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 June in 2011 and 2012 by airline.

Involuntary Denied Boarding/10K enplanements Airline 2011 2012 JetBlue Airways 0.01 0.01 Virgin America NA 0.05 Hawaiian Airlines 0.08 0.2 Delta Air Lines 0.29 0.41 Alaska Airlines 1.03 0.62 Frontier Airlines 1.02 0.74 US Airways 1.04 0.74 American Airlines 1.03 0.74 Southwest Airlines 0.78 0.91 Airtran Airways 0.43 0.92 American Eagle Airlines 2.92 1.27 ExpressJet Airlines* 0.76 1.93 United Airlines* 1.08 1.93 Skywest Airlines 0.66 2.07 Mesa Airlines 2.3 2.48

* United Airlines and Continental are combined (following their merger). ExpressJet Airlines and Atlantic Southeast Airlines are combined.