Birth tourism
Some countries do not allow their citizens to renounce their citizenship or only if the citizenship was acquired by birth there to non-citizen parents. In Argentina, Brazil, Ecuador, Peru, and Uruguay, voting is compulsory for citizens. In Bolivia, Brazil, Chile, Colombia, Cuba, Guatemala, Paraguay, and Venezuela, military service is mandatory.
Contingent vote
Today, a special variant of the contingent vote is used to elect the President of Sri Lanka. Another variant, called the supplementary vote, is used to elect mayors and Police and Crime Commissioners in England. In the past the ordinary form of the contingent vote was used to elect the Legislative Assembly of Queensland from 1892 to 1942. To date, this has been the longest continuous use of the system anywhere in the world. It was also used in the US state of Alabama in the 1920s.