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.
Instant-runoff voting
Because the ballot marking is more complex, there can be an increase in spoiled ballots. In Australia, voters are required to write a number beside every candidate, and the rate of spoiled ballots can be five times higher than plurality voting elections. Since Australia has compulsory voting, however, it is difficult to tell how many ballots are deliberately spoiled. Where complete rankings are not required, a ballot may become exhausted if none of the ranked choices on that ballot advance to the next round.