Sounds like a cool title, though greek mythos isn't the first thing I have in mind when it comes to the title, but maybe for something different.
Answer:
The airlines base the policy on the assumption that the consumer demand is less elastic as time of departure approaches.
Explanation:
Price Elasticity of Demand refers to price sensitivity; i.e. the rate at price changes with demand.
As the purchase and flight departure gets smaller, the arrival rate of the passengers will definitely change.
When the demand of a commodity is less elastic, then it will cause a large changes in price of that commodity to effect a change in quantity consumed.
