Assume American Airlines acquires a regional airline in the mid western United States for $450 million. American

Question:

Assume American Airlines acquires a regional airline in the mid western United States for $450 million. American Airlines allocates $150 million of the purchase price to landing rights at various airports. The landing rights expire in five years. What type of measurement is applicable to the valuation of the landing rights at acquisition and at the end of each of the five years?