America has decided: Sex is for rich people. Non-procreative sex in particular.

How else would you explain the trap we’re laying for poor people who deign to get it on?

Our country apparently doesn’t want low-income Americans to have free access to birth control, either by compelling all insurance plans to offer it or by adequately funding public reproductive health programs. In many schools — predominantly located in low-income, high-teen-pregnancy areas — we don’t even teach kids how contraception works. We also don’t want them to have easy access to abortions when they inevitably get pregnant because they’re not using birth control, with states such as Texas and Mississippi trying to shutter their few remaining abortion clinics.

Then we don’t help them very much after they birth those unplanned kids, instead publicly chastising irresponsible single mothers for having babies they can’t afford and offering little assistance in the form of child care, education or cash. Dumping unwanted children onto the child welfare system isn’t exactly celebrated, either.

By process of elimination, the solution for low-income people is to never, ever have sex. So seems the logic behind many of these policies: If only we make it harder for people to have access to family planning services, and financially painful to raise children who predictably result from sex in the absence of those services, people who cannot afford to raise children will choose celibacy.

This, of course, is magical thinking. The belief that we can get entire classes of Americans to practice abstinence until they’re financially ready for marriage and children is a right-wing delusion on par with the left-wing delusions that go into socialism: Both rely on a fundamental miscalculation about human nature. If the socialists wished to legislate away self-interest, the moralists wish to legislate away libido.

Data show just how difficult it is to keep those unmarried libidos in check. Tawdry though it may be, nearly 9 in 10 young, unwed adults have had sex, according to the National Campaign to Prevent Teen and Unplanned Pregnancy.

Which is why subsidies for family planning services make a good deal of sense. And when I say services, I mean not only financial access to contraception but also education about how it works. Study after study has documented astounding amounts of confusion and misinformation about baby-making. One in 5 unmarried young men, for example, incorrectly believes that having sex standing up is a form of birth control. Among women who have unintended births because they weren’t using contraception, about a third say they hadn’t thought they actually could get pregnant, perhaps because they’d had sex before and never previously landed “in the family way.” But who could really blame young’uns for their ignorance and silly extrapolations, when even a former congressman, Todd Akin, once declared that an effective form of contraception is a woman’s internal desire to “shut that whole thing down”?

It should be no wonder, then, that more than half of all pregnancies are unintended, and that the proportion is 70 percent for single women in their 20s, as Isabel Sawhill discusses in her thoughtful book, “Generation Unbound: Drifting into Sex and Parenthood without Marriage.”

Government spending on family planning offers a huge return on investment, not just for families but for the public. In 2010, every $1 invested in helping women avoid pregnancies they didn’t want saved $5.68 in Medicaid expenditures that otherwise would have been needed, according to the Guttmacher Institute. Once upon a time, both left and right understood this calculus. Title X, the federal family planning program that primarily serves low-income women (and whose funding has fallen 18 percent over the last decade, after adjusting for inflation) was passed under President Nixon with unanimous Senate support. Today this and other federal programs that democratize family planning (including the Affordable Care Act) are subject to constant gutting and mockery, with pundits referring to advocates of affordable birth control as “sluts,” and politicians asking why the state should be subsidizing “recreational” activities like sex.

America is increasingly turning into a two-track society when it comes to fertility decisions, with high-income, highly educated Americans availed of better and more options (even, it turns out, employer-provided egg-freezing services); and low-income women drifting into childbearing that they themselves say they’re not ready for. Despite what opponents say, improving access to family planning services and reversible contraceptives is not about encouraging sex — biology takes care of this already — or that false boogeyman of sterilization. It is about giving low-income women the same control over when, and with whom, they have children, as is afforded to their higher-income sisters.