Electoral system
Electoral rules place limits on suffrage and candidacy. Most countries's electorates are characterised by universal suffrage, but there are differences on the age at which people are allowed to vote, with the youngest being 16 and the oldest 21 (although voters must be 25 to vote in Senate elections in Italy). People may be disenfranchised for a range of reasons, such as being a serving prisoner, being declared bankrupt, having committed certain crimes or being a serving member of the armed forces. Similar limits are placed on candidacy (also known as passive suffrage), and in many cases the age limit for candidates is higher than the voting age. A total of 21 countries have compulsory voting, although in some there is an upper age limit on enforcement of the law. Many countries also have the none of the above option on their ballot papers.
Mandated choice
Mandated choice or mandatory choice is an approach to public policy questions in which people are required by law to state in advance whether or not they are willing to engage in a particular action. The approach contrasts with "opt-in" and "opt-out" ("presumed consent") models of policy formation. The approach has most frequently been applied to cadaveric organ donation, but has increasingly been considered for advance directives as well. One bioethicist, in advocating for a mandatory choice model for living wills, argues that "while all Americans should have a right to decide how they want their lives to end, it does not follow that they should be able to avoid confronting such a choice."