A group of economists has found that women who had better access to the pill were earning 8 percent more than those who didn't by the time they reached age 50. Another reason, maybe, for why women should have birth control covered by their insurance? 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.  
In short, women on the pill are better able to get degrees, choose their occupation, and enter (and leave) the workforce when they want, which in turn gives them better footing with men in terms of commanding wages. "Our estimates imply that the pill can account for 10 percent of the convergence [of] the gender gap in the 1980s and 30 percent in the 1990s," write the researchers. At 80 cents to each $1 a man earns in 2009, that gender wage gap is hardly closed, which is why this statistic (like others) has reentered the contraception troll-fest debate, with The New York Times calling back to it today.