 Marriage is the basis for legal discrimination in a number of contexts; such discrimination requires justification, as does the resource allocation involved in providing marital benefits (Cave 2004, Vanderheiden 1999). In the absence of such justification, providing benefits through marriage may treat the unmarried unjustly, as their exclusion from such benefits would then be arbitrary (Card 1996). Thus, there is an onus to provide a rationale justifying such resource allocations and legal discrimination on the basis of marriage, as well as for restricting marriage in ways that other contracts are not restricted.