For some types of taxes, in particular where the tax base is mobile or straddles more than one jurisdiction, the possibilities for evasion and avoidance increase with decentralization. In the case of multidistrict bases, rules are needed to allocate tax revenues among jurisdictions, for in their absence, some tax bases may face either double taxation or no taxation at all. Auditing procedures may also be more difficult for tax bases that involve transactions across state boundaries.