Oh, the fun tax theory exam questions that could flow from this! Recall that the naive interpretation of Ramsey tax theory says that you want to tax more heavily those goods that are inelastic in demand: that way, deadweight costs are lower. But the more accurate interpretation of Ramsey (here too) is that you want to tax more heavily those goods that are complements to untaxed leisure in a world in which we can't tax leisure directly. Further, we have Pigovean reasons for taxing public bads and subsidizing public goods.
So, is the Pill a complement to leisure or to labour? Tyler points to some evidence from the paper's abstract:
Women who lack insurance and have sex infrequently appear to substitute toward emergency contraception; uninsured women who are frequent sex participants appear to substitute toward non-prescription forms of birth control. Additionally, we find small but significant decreases in frequency of intercourse and the number of sex partners, suggesting that some women may be substituting away from sexual behavior in general.If intercourse is leisure rather than investment in work-related social capital, then we might have some Ramsey argument for taxing contraception. But it's not immediately clear in which direction any Pigovean argument might run. Neither is it even immediately clear in which direction any long-run Ramsey argument might run if you think through some general equilibrium arguments about sex, positional goods, and hypergamy; easy to imagine how it could go either way.
There's at least a short essay exam question in there on tax theory for anybody who's lecturing tax in public economics next year; it's a nice one where there are lots of clearly wrong answers but also many potentially right answers so long as the argument is reasonable.
Happy Valentine's Day!