The trio of researchers from the Universities of Michigan and Virginia found in a study from last December that women aged 18 to 21 who lived in states with better legal access to oral contraceptives in 1970 had hourly wages that were 8 percent higher than peers in less pill-friendly states by the time they reached their late forties. Their explanation of why access to the pill translates to higher incomes:
Consistent with the well-known relationship of women’s wage growth to cumulative labor-force experience, our decomposition indicates that almost two thirds of the Pill-induced wage premium at the mean is explained through its effect on women’s labor-force experience. Another third of the premium is due to changes in educational attainment and occupational choice.
It's almost like if you allow women to decide when and if they have kids, they're better able to provide for those kids. Plus be productive wage-earning tax payers. Weird.