As a legal construct, the leasehold estate is a versatile and profoundly useful tool. As a creature of the law of contract and of real property, it is in principle the perfect vehicle for an exchange economy. It allows the landlord to release locked capital, and the tenant to swap personalty for realty. It is ideal for property investment. The parties to a lease can trade possession and responsibility, in the long or short term, and they can choose the level of their commitment to each other through their leasehold covenants. The leasehold should be revered as the embodiment of the flexibility and pragmatism of the common law.