The regulation of rents charged for mobile home park spaces constitutes a special category of rent control. The legitimacy of rent controls has always been in question in the United States on ideological and policy grounds. However, mobile home space rent controls have generally been considered more legitimate than apartment rent controls, due to the captive nature of mobile home tenancies and the large investments by the tenants. The mobile home space rent controls in California differ from apartment rent ordinances in some critical aspects. The rent control ordinance, the judge said, created a transferable possessory interest that had a “market value,” and this possessory interest distinguished the mobile home rent control scheme from conventional apartment rent controls. A few years after Los Angeles, San Francisco, Oakland, and San Jose adopted apartment rent control laws in 1978 and 1979, mobile home space rent ordinances were also enacted.