Final answer:
The property owner who sold the mineral rights has given up their subsurface rights. Retaining other rights, the transaction has clearly defined who owns the mineral rights now, in accordance with Ronald Coase's theory on the importance of clear property rights.
Step-by-step explanation:
When a property owner sells the mineral rights to their land, they are giving up their subsurface rights. This means that while they may still own the surface land, they no longer have the legal rights to the minerals beneath the surface. The owner retains other rights, such as air rights, the right of possession of the surface, and the right to lease the property unless those rights are also expressly conveyed. In reference to the thoughts by the economist Ronald Coase, this transaction has clearly defined the property rights by legally transferring ownership of the mineral rights, ensuring that others cannot infringe upon these rights without proper compensation.
In the context of Ronald Coase's work on property rights, the definition and clarity of legal responsibilities are crucial for avoiding disputes and ensuring that parties are responsible for the costs associated with their owned properties or assets. When rights are well-defined, as in the sale of mineral rights, it clearly delineates ownership and the associated responsibilities, thereby mitigating potential conflicts and inefficiencies.