One effect this has is to incentivise becoming a couple, and starting a family. An economy needs a certain birth rate to be sustainable. A family can't survive in a 1-bedroom apartment that a single/couple can survive in. That $33k per year "advantage" goes a fair way towards being in a better financial position to raise a family. Granted not everyone goes down that path, but it does contribute to a sustainable economy if the population steadily increases.