As we blackpillers know, the solution would be the exact opposite, Taliban style. If you really wanted to fix declining birthrates, you'd take all money, jobs, choices, and opportunities away from women, and force women to get married, ban polygamy, and ban sex out of wedlock. You'd have to eliminate all ability for women to have access to Chads and ignore non-Chads. Make unmarried women the equivalent of lepers of society, and haul their skanky asses off to a whore house if they aren't married by age 18.