In a Life Estate Pur Autra Vie, whose life span determines the tenancy?

In a Life Estate Pur Autra Vie, the tenancy is determined by the life span of a specified individual, also known as the measuring life. This type of life estate grants the life tenant the right to use and benefit from the property during the lifetime of this specified individual, after which the property will pass to another party, typically referred to as the remainderman.

The reason this answer is correct is that the essence of a Life Estate Pur Autra Vie is that it is contingent upon the life of someone other than the life tenant. This means the rights afforded to the life tenant are directly tied to the duration of that specific individual's life, thereby defining the length of the estate.

The other individuals mentioned, like the life tenant or the remainderman, do not have their lifetimes affect the nature of this estate in the way that the specified individual does. The average life expectancy also does not play a role in determining the tenancy; rather, it is the actual lifetime of the person designated in the arrangement that determines when the life estate terminates.