Commensurability in economics arises whenever there is a common measure through which the value of two entities can be compared.

Commensurability has two versions:
* Strong commensurability arises when it is possible to give cardinal values to entities as a consequence of utilising a given property to measure entities. Thus we can say "This is two and a half times more valuable than that." This implies value monism.
* Weak commensurability arises when it is only possible to apply