The voluntary way of capturing future ROI with present investment is loans (or if you don't care about ROI, donation). Now I'm not saying that is necessarily the only option but it's the one you're gunning for based upon your economic argument.
Based on your criteria it's the most textbook case for an individual loan imaginable, your argument is the 22 y/o needs a loan for some healthcare, that he can more than pay it back, and that both parties will benefit. In the absence of charity, some kind of trade, family or friend assistance, then in any rational market (US market is regulated to hell so no guarantee it works there unless you free that market) it's a no brainer and as sure as an apple will fall from a tree, someone would be happy to make that trade although the kinetics and packaging might be up for debate.
I don't see how you can possibly presuppose a requirement for public assistance, in that scenario, in order for the health care to happen. Public assistance is only economically necessary to complete the health care if there is negative ROI and all donation or voluntary options are exhausted.
Based on your criteria it's the most textbook case for an individual loan imaginable, your argument is the 22 y/o needs a loan for some healthcare, that he can more than pay it back, and that both parties will benefit. In the absence of charity, some kind of trade, family or friend assistance, then in any rational market (US market is regulated to hell so no guarantee it works there unless you free that market) it's a no brainer and as sure as an apple will fall from a tree, someone would be happy to make that trade although the kinetics and packaging might be up for debate.
I don't see how you can possibly presuppose a requirement for public assistance, in that scenario, in order for the health care to happen. Public assistance is only economically necessary to complete the health care if there is negative ROI and all donation or voluntary options are exhausted.