How to give more power to the young

A democracy, and in particular a representative democracy, suffers from the problem that the interests of older people are over-represented. This is first because many young people cannot vote (yet), and second because the opportunity cost of voting is lower for retirees. The consequence is that policies are tilted towards the interests of the older generation, with a shorter horizon especially. How could one adjust policies to reflect better the interests of all the population?

Kazumasa Oguro and Ryo Ishida suggest that one should adjust the voting to achieve more representative policies. Specifically, instead of attributing seat to geographic areas, they should be given to population cohorts. This takes care of only part of the issue, as current policies have an impact on future generations that are not yet voting. For this, one needs to gives relatively more seats to the younger cohorts, the allocation being proportional to the expected remaining lifetime. Not surprisingly, this reform would lead to more forward-looking policies and more growth. But, how to get a majority to vote for such a democratic system?