Demeny voting

Demeny voting is the provision of a political voice for children by allowing parents or guardians to vote on their behalf. The term was coined by Warren C. Sanderson in 2007. Under a Demeny voting system, each parent would cast a proxy vote, worth half a vote, for each of their dependent children, thus allowing for a split vote if the parents' political views differ. Once children reach the minimum voting age, their parents would no longer vote on their behalf.
History.
Demeny voting is named after demographer Paul Demeny, who came up with the idea in 1986. Demeny argued that children "should not be left disenfranchised for some 18 years: let custodial parents exercise the children's voting rights until they come of age". Demeny's motivation behind proposing such a system was to "make the political system more responsive to the young generation's interests" and was part of a broader set of policy proposals aimed at combating the low fertility rate in certain countries.
The idea, however, is older than Demeny's idea; it was regularly discussed in France in the 1920s and was almost adopted by the National Assembly.
In Germany the idea was even first discussed in the 1910s. In the 1970s and the 1980s lawyers and political scientists began a discussion which is still going on. In
2003 and 2008 the German parliament had votes on whether to introduce a "Kinderwahlrecht" (which is the term in German), but the proposals were defeated. In 2011 Hermann started a comprehensive economic approach to discuss it.
Pieter Vanhuysse (head of research and Deputy Director at the European Centre for Social Welfare Policy and Research, Vienna) argued in 2013 that in Austria, where there are relatively strong pro-elderly policies, that "the time is ripe for at least opening a clear-headed and empirically informed democratic debate about the radical idea of giving each parent one half extra vote, to be used on behalf of each under-age child until that child reaches legal voting age".
Japan has discussed Demeny voting as a possible answer to its aging population, which gives disproportionate voice to the elderly as a result of their increasing numbers. This follows the publication of a paper by Reiko Aoki of the Centre for Intergenerational Studies at Hitotsubashi University and Rhema Vaithianathan of the University of Auckland. On 2 March 2011, the Centre for Intergenerational Studies at Hitotsubashi University hosted a conference on Demeny voting. Aoki and Vaithianathan have also conducted a number of surveys on voter attitude to Demeny Voting and found that a considerable percentage of respondents would cast their children's vote differently to their own. In July 2013, Nikkei in Japan wrote a major editorial supporting the idea as part of a debate on constitutional reform in Japan.
In Hungary, the ruling coalition has been advocating Demeny voting, but admitted in April 2011 that it probably won't come into practice for some time.
Paul Demeny discussed the idea on a CBC interview. Professor Miles Corak from the University of Ottawa has also written a blog on the idea and promoted it in Canada. He suggests that it is supported on a humanitarian basis since the UN Convention on the Rights of the Child provides that children be given civil and political rights. He suggests that given the evidence that households where mothers control the purse-strings spend more on their children, it is mothers who ought to be given the proxy vote until the child comes of age. Professor Corak's thesis has been taken up by journalist Chrystia Freeland .
Advantages.
Aoki and Vaithianathan argue that Demeny voting is justified because it reduces gerontocracy. They calculate that Demeny voting in Japan would increase the parent voting bloc from 24% to 37% and lower the over-55-year-old voter-bloc from 43% to 35%.
Stefan Olsson argues that "the delegation of the children's right to vote is not any stranger than when adults delegate political authority to their elected representative. After the election, the representatives have the right to make use of this authority." (page 71). He suggests that delegating a child's authority to the parent is perfectly reasonable. Olsson also argues that there are other areas where parents are delegated authority such as what the child eats, where he goes to school, and children are regularly represented in a court of law by parents. He says that "Arguing that parents cannot act as their children's representative because they might abuse their position becomes absurd in comparison to all the other powers parents already have over their children." (page 72).
It has been suggested it would make it harder for elderly voters to vote in governments that borrow money for social security but which will only be paid back by future generations. It may ensure that the needs of children, such as education, childcare, and healthcare, are better taken into account. It could also make governments more ecologically conscious as younger people will be more affected by poor environmental policy than older voters. Finally, extending the vote to children may increase their involvement in politics, encouraging children to grow up and be more active citizens.
Disadvantages.
Opponents see Demeny voting as a violation of a fundamental normative principle of democracy: 'one person, one vote'. They point to the fact that children below the minimum voting age can hold different political opinions and thus prefer different parties to their parents. There is no evidence that parents would split their votes. Instead, they would have plural votes for the same party they prefer (and have formerly preferred).
Some writers argue that, like marrying or making a will, voting is an exercise of the informed will and cannot legitimately be done by proxy. Others have argued that with the right to vote comes other obligations of citizenship, such as military service. Since children do not have those obligations, it is argued they should also not have such rights. Some people worry that the power of older votes will be diluted and the interests of children might be prioritised above those of the elderly.
Yet others have argued that lowering the voting age to 13 or 14 or lower would be more beneficial, as many children are able to express complex opinions at that age.
Some scholars advocate a 'flexible voting age' building on the willingness of minors to participate in elections. The ‘flexible voting age’ proposal contains a need for adolescents to register in voting lists and so differs from proposals that come under the name of ‘voting from birth on’ or ‘voting age zero’. It takes into account that infants, small children and many younger adolescents will have no interest in political participation. 
Jon Elster has argued that if the justification for Demeny is on the basis of consequences, then said consequences should be voted on, rather than changing the voting demographic. His argument is that to advance Demeny voting on the grounds that it leads to desirable consequences is pointless, since it will be blocked by exactly those groups who will block the desired consequences (e.g. raising the pension age).