An interesting thought, and I’ll have to dwell on it, but my first reaction is I’d like to avoid the bureaucracy and value judgments that would accompany that sort of policy. I think an equal chunk of money upon 18 (or 19, or perhaps emancipation age if younger) would be easier to pass, implement, and maintain. For people with ambitious goals, like start up businesses, they can still go through the process of raising extra funds to do so if needed.