How about voluntary vasectomies paid for by charitable organizations, offering each man, say, $1,000 cash?
Yes, there’d have to be procedures to prevent fraud. And of course one would need to put in place all the necessary safeguards for voluntariness, including massive notice that the procedure is usually irreversible, have nice, clean, modern clinics doing the procedure, etc.
If a man voluntarily would take $1K from a private charity in exchange for a lifetime of fathering fatherless children, why not? Is it unethical for him to have that choice?
I would have no objection. There is a private organization, Project Prevention, that does just that for substance abusers: www.projectprevention.org