Minimax Regret and my flight home

As we all enjoy these “reading days,” many of us will be leaving C-Ville to travel. Yesterday, I flew home to Connecticut on the 8pm flight. Now anyone who has been through airport security knows it’s a crap-shoot whether the lines are unbearably long or not. My father, ever the pessimist, is a firm believer in arriving 3 hours early to the airport for international flights and 2 hours early for domestic flights, to ensure you make it through security in time. Because of this philosophy, I have spent many family vacations sitting in an airport gate, hours early, waiting for a flight that would likely be delayed anyway. Don’t tell my parents this, but instead of using my dad’s hard and fast rule of “2 hours early,” I decided to use the minimax regret table instead to decide what time I should leave for the airport.  The two alternatives are 1) leave late 2) leave 2 hours early. The two states are 1) make the flight 2) miss the flight.

The cost of my ticket was around $200, but this is a sunk cost. However if I missed my flight because I left late that would be like losing $500,000. This is because my parents would NEVER let me live down the fact that I missed my flight home because I recklessly left my apartment too late. However if I left too early, and was stuck waiting at the gate, this would be pretty inconvenient. By following the “2 hour rule,” I would probably be waiting for one and half hours at the gate minimum. If I value my time at $20 (my usual babysitting hourly fee), then it would cost me around $30. However, going home is worth at least $100,000 because this is one of the last times I can visit before my parents sell the house and move to South Carolina. Therefore, this event would be worth $99,970 in total. If I leave 2 hours early and still miss the flight, I can at least defend myself against my parents and say that I tried to follow my dad’s advice. This would save me the $500,000 cost of my parents scolding me, so there would be no regret. Using the table, it is obvious I would minimize regret by following my dad’s advice and leaving 2 hours early. Sadly this exercise taught me that my parents are always right.

	Make the Flight	Miss the Flight
Leave Late	0, no regret	($500,000)
Leave 2 hours early	$99,970	0, no regret