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Literally Inconceivable: Contraceptives And Abortion Rates

I have amazing parents who would never do something sneaky like install a keylogger on my computer to keep tabs on me as I move thousands of miles away from home. But if I’m wrong and they did do that, they’re probably sweating pretty hard right now. My search history for the last two days looks a lot like “efficacy of contraceptives”, “contraceptive failures”, “pregnancy risk if contraceptive failure”, “unintended pregnancy”, “unintended pregnancy abortion”, and “COME ON GOOGLE WHY WON’T YOU GIVE ME GOOD INFORMATION ON UNINTENDED PREGNANCIES AAARGH”

(this last one brings up a address, which does not surprise me one bit)

My parents can relax – the searches are because of the comments on a recent post of mine. In response to a claim that pro-lifers should be in favor of contraception since it decreases abortions, I argued that moral philosophy doesn’t always work that way, but let the main point – that contraception decreases abortion – stand. Some people, especially Joe and Gilbert, challenged my assumption, leading to an unpleasant wade through the swamp of contraception-related data.

The Anti-Contraceptive Position

Let’s start with the nay-sayers. In what he claims is a long essay (ye call that long? I’ll be showin’ ye long!) Bad Catholic evaluates correlation between abortion and contraception rates in different countries. He finds – mostly using data from the pro-choice Guttmacher Institute, a huge clearinghouse of abortion data we will be returning to again and again – that:

Contraception has been shown to decrease abortion rates primarily in [ex-Soviet bloc] countries with already high abortion rates. These represent a minority of countries. Contraception has been shown to increase abortion rates primarily in [non ex-Soviet bloc] countries with already low abortion rates. These represent a majority of countries. Contraception has been shown to slightly reduce abortion rates after its initial increase of abortion rates, but has never been shown to reduce abortion rates back to pre-contraception levels. This is my claim. I have no doubt that there’s a lot more to say, given the incredible amount of studies I haven’t seen. But as far as I can tell, this is a claim far closer to the truth than the oft-repeated, always unexamined “Contraception reduces abortion rates”.

This at first sounds bizarre – how could contraception, a technology that decreases unintended pregnancy – increase abortion, a result of unintended pregnancy? Enter the Peltzman effect, aka risk compensation.

I have a deep love for the Peltzman effect. Part of this is that it’s one of the few terms we social scientists have that sounds as nifty as the one physicists and mathematicians bandy around all the time. Another part is that a girl messaged me on OKCupid once explaining the Peltzman effect to me and asking me on a date (I never claimed my life was normal). But the rest of it is that it’s jsut this really elegant and unexpected finding where across a broad set of domains people respond to hard-won advances that make them safer with “Cool! Now I can behave irresponsibly!” It’s been found with anti-lock brakes (drivers drive closer to the car in front of them), with seat belts (people just drive faster), and with childrens’ safety gear (children just behave more recklessly).

The Peltzman effect doesn’t always hold true; sometimes we expect it and can’t find it. And it rarely makes things worse – it usually is cited as keeping things at the same level they were before, and one well-studied exception, the Munich taxi study, only finds a tiny increase in accidents.

But inside view here – how many people here, if they don’t want kids, would be willing to have totally unprotected sex? And how many people would be willing to have sex using condoms? But condoms have a typical failure rate of 15% – meaning that if a couple has sex for a year using only condoms for protection, there’s a 15% chance the woman will get pregnant. With combined oral contraceptive pill, it’s 8%. So if these contraceptive methods make people about ten times more willing to have sex when they don’t want pregnancy – not at all hard to imagine! – they could raise the unintended pregnancy rate and therefore the abortion rate.

This is the context of Joe’s study showing that in Spain from 1997 – 2007, a large rise in contraceptive usage occurred simultaneous with a large rise in abortion.

A few other arguments seem transparently stupid to me – for example, some people like to point out that US states with high contraception rates also have high abortion rates, but that’s mostly a feature of those states being very liberal and so allowing abortion clinics to operate there. So lets move on to…

The Pro-Contraceptive Position

Just in case you thought you were going to escape without any graphs:

Here’s teenage birth rates over the last 75 years. Like nearly all social problems, they have been steadily and somewhat mysteriously declining, but we notice an especially sharp decline around 1960, the year the Pill was introduced. Abortion wasn’t legalized until the 70s and was pretty uncommon before then, so we can leave it out of this analysis and say that it sure looks like the invention of a new form of contraception decreased pregnancies.

Also near an all-time low are abortion rates (I assume they mean “all-time low since abortion was legalized”?). This seems to be due to both fewer unintended pregnancies and less willingness to end unintended pregnancies with abortion. Santelli et al 2002 find the decline to correspond nicely to increasing use of contraceptives. Some pro-lifers claim (data unavailable), that after 2002 abortions continued to drop even though contraception use stayed steady. Unfortunately, all I can find is the CDC saying contraceptive use continued to rise – in the absence of their contrary data, I’m giving this point to the “increased contraception helped reduce abortion” people.

(one way that we could reconcile these two results, if we were feeling very generous, is to say that overall contraception use has remained the same, but users have switched to more effective modern forms of contraception like the implant or IUD, with a failure rate less than 1/100th that of condoms)

But this is actually consistent with Bad Catholic’s claim above – contraception increases the abortion rate when first introduced, then eventually stabilizes and decreases it, but never back to the level before contraception. So let’s evaluate that one. Bad Catholic writes:

An honest look at the data shows that in virtually every country that increased the use of contraception, there was a simultaneous increase in that country’s abortion rate. In England (Rise in contraceptive use: simultaneous rise in abortions), France (Rise in contraceptive use: simultaneous rise in abortions), Australia, (Rise in contraceptive use: simultaneous rise in abortions), Portugal (Whose abortion rate only began to rise after 1999, after oral contraceptive methods were made widely available), Canada (Whose abortion rate only began to rise after the legalization of oral contraceptives in 1969), and, as the Guttmacher Institute shows, Singapore, Cuba, Denmark, the Netherlands, and South Korea, to name a few.

Let’s investigate the countries in order. The claim seems to be only that abortions and contraceptive use rose “simultaneously”, but following his links this turns out to mean “throughout the 20th century”. There is no attempt to prove that the particular shape of the contraception curve matched that of the abortion curve or anything like that, just that there was more contraception in 2000 than in 1950, and, whaddya know, more abortions as well. The same methodology could very easily correlate abortion with global temperature. His statistics on England, France, and Australia all seem to be of this type.

He makes a stronger claim about Canada: that “the abortion rate only began to rise after the legalization of oral contraceptives in 1969”. You know what else was legalized in Canada in 1969? Abortion. I’m going with “probably not a good test case”.

As for Portugal, the claim that oral contraceptive methods were legalized in 1999 seems wrong; his own link says they have been available since 1985 and that only the emergency contraceptive pill was made available in 1999. Further, his claim that “abortion rates only began to rise after 1999” also seems wrong – his link shows what looks like a pretty linear rise in abortion rates from 1996 to 2006; I don’t think anyone eyeballing those numbers would be tempted to consider 1999 anything remotely like an inflection point. My own guess for an inflection point would be 2007, and sure enough when I Google it that was the year they fully legalized abortion.

The Guttmacher Institute doesn’t link to its sources as diligently as Bad Catholic, so I’m just going to accept their claim that six countries – Singapore, Cuba, Denmark, Netherlands, US, and South Korea – saw simultaneous increases in contraception and abortion – after all, it goes against the direction of their bias so they have no incentive to lie. They give their results the following explanation:

The reason for the confusion stems from the observation that, within particular populations, contraceptive prevalence and the incidence of induced abortion can and, indeed, often do rise in parallel, contrary to what one would expect. The explanation for these counterintuitive trends is clear.2 In societies that have not yet entered the fertility transition, both actual fertility and desired family sizes are high (or, to put it another way, childbearing is not yet considered to be “within the calculus of conscious choice”3). In such societies, couples are at little (or no) risk of unwanted pregnancies. The advent of modern contraception is associated with a destabilization of high (or “fatalistic”) fertility preferences. Thus, as contraceptive prevalence rises and fertility starts to fall, an increasing proportion of couples want no more children (or want an appreciable delay before the next child), and exposure to the risk of unintended pregnancy also increases as a result. In the early and middle phases of fertility transition, adoption and sustained use of effective methods of contraception by couples who wish to postpone or limit childbearing is still far from universal. Hence, the growing need for contraception may outstrip use itself;4 thus, the incidence of unintended and unwanted pregnancies rises, fueling increases in unwanted live births and induced abortion. In this scenario, contraceptive use and induced abortion may rise simultaneously.

As fertility decreases toward replacement level (two births per woman), or even lower, the length of potential exposure to unwanted pregnancies increases further. For instance, in a society in which the average woman is sexually active from ages 20 to 45 and wants two children, approximately 20 of those 25 years will be spent trying to avoid pregnancy. Once use of highly effective contraceptive methods rises to 80%, the potential demand for abortion, and its incidence, will fall. Demand for abortion falls to zero only in the “perfect contraceptive” population, in which women are protected by absolutely effective contraceptive use at all times, except for the relatively short periods when they want to conceive, are pregnant or are protected by lactational amenorrhea.5 Because such a state of perfect protection is never actually achieved, a residual demand for abortion always exists, although its magnitude varies considerably among low-fertility societies, according to levels of contraceptive use and choice of methods.

This seems incredibly reasonable, and we will come back to it later. Let’s abandon all of these time series type studies and see if we can find a halfway-decent controlled experiment.

Well, uh…we can find a controlled experiment. These people in St. Louis gave people free contraceptives and later found that they had a teenage pregnancy rate much lower than the rest of the population. Gilbert gives this study exactly the correct criticism – participants from a very specific population (poor people in St. Louis interested in signing up for a contraceptive study) are being compared to the general population (everyone in the United States). This is inexcusable, especially considering that Real Science has an extremely standard way of avoiding this problem (sign people up for your study, only give the intervention to a randomly selected half, and the other half is an instant control group). Other fatal issues – the study used IUDs, the most effective form of contraception, but most of the worry that contraception might increase abortion comes from less effective means like condoms and the Pill. Finally, if you’re really interested in the way that widespread availability of contraceptives makes a culture more libertine, just giving them to a couple of people within that culture isn’t going to capture that effect. I am maybe a little bit hugely disappointed that most of the media and bloggers reporting on this didn’t mention these sorts of issues.

But it does show one interesting thing, which is that when people get free contraception, they start using more effective contraception methods. Would this also cause risk compensation? I don’t know, but I feel like there has to be some amount of sex beyond which it’s just no longer fun, and some contraceptive methods are so effective that it would be really hard to have so much sex that they’re worse than nothing.

Let’s close this section with a few minor points.

Contraceptive advocates point to the Netherlands, with one of the lowest abortion rates in the world. Given the stereotypes of the Dutch, they probably didn’t get that way through careful abstinence, and indeed their government is unusually generous in providing free contraceptives.

It turns out people can just survey women having abortions and ask them if they used contraceptives or not! 54% of abortion patients were using contraception at the time, which pro-life websites get very excited about: “IT’S MORE THAN HALF!” But putting these numbers in context may diminish their enthusiasm: the four-fifths of American women who use contraception account for 54% of abortions; the fifth of women who don’t use it account for the other 46%. The Guttmacher Institute gets more or less the same numbers, but frames them in a very convincingly pro-contraceptive way:

The two-thirds of U.S. women at risk of unintended pregnancy who use contraception consistently and correctly throughout the course of any given year account for only 5% of all unintended pregnancies. The 19% of women at risk who use contraception but do so inconsistently account for 44% of all unintended pregnancies, while the 16% of women at risk who do not use contraception at all for a month or more during the year account for 52% of all unintended pregnancies.

So it seems clear that the more (and better) you use contraception, the less likely you are to have an abortion.


I think we can use these results to build a consistent picture.

Contraceptive and abortion rates often rise simultaneously. This rise is not necessarily causal, and is more likely to be due to both being parts of the same philosophy – people want to have lots of sex but not have kids. As this philosophy becomes more widespread, as it has nearly everywhere in the 20th century with the Sexual Revolution and Demographic Transition, both contraception and abortion will rise. As it gains ground, both contraception and abortion will become more legal and available, making them rise even further. It is unclear to what degree the availability of contraception itself causes the rise of this philosophy. I’m intrigued by this claim that penicillin rather than the pill started the Sexual Revolution, but if someone wants to claim that it was all due to contraceptives, I don’t have enough expertise in the area to prove her wrong.

On the other hand, once a society has undergone this transition and settled on “lots of sex, few kids” as being its dominant values, then the local application of more contraception seems to decrease abortion rates. We know this because of the surveys of abortion patients saying they are disproportionately likely not to be contraceptive users. We know this because of the decline in teenage pregnancies with the advent of the Pill. And we also notice the game-changing nature of new, more effective contraceptives with near-zero failure rates replacing older, more fallible ones, and the not-provably-causal but certainly suggestive secular decline in abortion rates that corresponds with that replacement.

Overall my guess would be that a society that legalizes contraceptives would see an increase in abortion rates (which might or might not be causal depending on that society’s situation), but that in a society like our own, where contraceptives are already legal and the demographic transition is pretty much complete, increasing access to contraceptives is probably going to decrease abortion. And increasing access to extremely effective contraceptives like the implant or RISUG, especially when they replace less effective contraceptives like the condom, are very very probably going to decrease abortion.

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51 Responses to Literally Inconceivable: Contraceptives And Abortion Rates

  1. Douglas Knight says:

    Nitpick: Americans post-2002 did not switch to the implant, because the implant was withdrawn from the market in 2002.

    You are right to dismiss the time series of most of the countries Bad Catholic mentions, but you skipped Turkey, which seems like the cleanest one.

    It’s a pity that the St Louis study was not randomized, but as an alternative to characterizing them as “interested in signing up for a contraceptive study” you could say “a population having a past pregnancy rate of 1 and an abortion rate of 0.4”

    • Kevin says:

      Nitpick of the nitpick: Norplant is not the only birth control implant. Implanon/Nexplanon is still on the market.

    • Cat says:

      Indeed, Impanon/Nexplanon (the same contraceptive by the way, Nexplanon was developed to be easier to insert and decrease failure rates) are the ones presrcibed by the NHS in the UK. Norplant’s old school.

  2. Mary says:

    Increasing access to contraceptives? Increasing it to what? In what way are contraceptives limited that would cause a meaningful increase in usage if it were removed?

    • Scott Alexander says:

      Most of the time I hear this discussed it involves giving them for free to poor people, like was done in the study mentioned above.

    • Patrick says:

      Cost and education.

      • houseboatonstyx says:

        And requiring a prescription, which requires a doctor’s exam, often including a pelvic exam.

        Brazil allowed contraceptives without prescription; many other things changed at the same time.

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      • Mary says:

        Any investigation of teen pregnancy finds the mothers can recite everything you could possibly dream of educating them about contraception.

        • Scott Alexander says:

          I can’t cite a source, but somewhere in reading like a hundred articles on contraception yesterday I found one that described the opposite – researchers talking to teens and findng they held ridiculous and dumb misconceptions about contraception.

          I’m gonna trust them over you, just because it would be weird if this were the ONE topic teens didn’t find a way to be ridiculously misinformed about 😛

        • Berry says:

          How many anecdotes about my fellow teenage friends knowing nothing about contraceptives would you like me to provide you with?

        • Kevin says:

          It is well-known that the US states with the highest teen pregnancy rates also tend to be the states that do not require accurate, comprehensive sex education. (See, e.g., these maps from Guttmacher studies.)

          There are also direct results that abstinence-only programs (which often tell outright lies about contraception) discourage contraception use among teens without actually discouraging sex, thereby increasing teen pregnancy rates.

        • Berry says:

          @Kevin: I believe Scott looked over the evidence for and against sex-ed in his old blog.

        • super-anonymous says:

          I’m not a teen mother, but I had to look up what “IUDs” are, if that tells you anything.

    • naath says:

      *license new methods (like RISUG) so there’s a better choice.
      *ensure more doctors are qualified to administer long-term contraception such as Implanon or Mirena (in the UK essentially any GP will write out a prescription for the Pill but if you want longer acting methods you might have to go to a specialist)
      *ensure that doctors understand and respect patient confidentiality, especially for teens. Including their billing department!
      *ensure that people who want contraception know that it exists, what types there are, where they go to get it etc.
      *ensure that it is possible for people to actually get to doctors without difficult travel – especially important for people who don’t/can’t drive; which includes people too young to drive.
      *lower the cost of the whole experience of getting contraception
      *raise the social acceptability of using contraception; peer pressure and social shaming may be putting people off using contraception. Especially condoms.
      *raise the level of parental acceptance of their young adult children using contraception

    • Cat says:

      You have to pay for LARCs in the States right? Or they’re less affordable according to your health plan? Well yes, free contraceptives for everyone. LARCs advised first instead of the Pill, education in sex ed in schools on all contraceptives. I went to high school in the UK, where there was no kind of abstinence programme whatsoever, but they still only taught us about condoms. I wish someone had given me an overview of my options in my teens, it would have saved me alot of stress and panic over pregnancy scares. I educated myself about LARCs when I was 17 and got an implant.

  3. JJJ says:

    Condoms are pretty damn cheap. $35 will get you a 144 pack variety bowl at Wal-Greens. That’s 3 minutes of minimum wage per condom. And if that’s too expensive for you, there’s alternatives to penis-in-vagina sex. The price of birth control is a trivial inconvenience* not a barrier to access.


    • JJJ says:


    • Scott Alexander says:

      Condoms are also relatively ineffective and easy to forget. I personally know sexually active people who can’t get IUDs because of cost.

      • coffeespoons says:

        Condoms are pretty effective if you use them correctly (something like 99% or 98%). All correct use means is putting it on as per the instructions and using it everytime you have sex. The 15% figure, I believe, comes from people not actually using condoms every time they have sex, and not following the instructions. You can ususally tell if they’ve failed as well, because they break, or fall off. If that happens taking the morning after pill is a good plan.

        I have relied on condoms since I started having sex. I have had quite a lot of sex, but they have only failed twice, and I took the morning after pill both times. I have never been pregnant. Of course I may well be infertile, but many of my female friends have also often relied on condoms and they haven’t become pregnat, and I doubt we’re all infertile!

        • coffeespoons says:

          It might be that it’s really difficult to educate people on how to use condoms correctly, so that as a public health measure condoms are not brilliantly effective. However, on an individual level, learning how to use condoms effectively and using them every time is a really good idea.

        • houseboatonstyx says:

          Steve Jobs used to say, “The best computer is the one that gets used.” Condoms, however cheap or free, aren’t very good at actually getting used consistently or correctly by large enough numbers of people.

        • coffeespoons says:

          houseboatonstyx – I have never had sex without a condom. And it’s not as if I’ve always been totally sensible. When I was younger, several drunk one-night stands (with people in my wider friendship group) for instance. The thing is, I normally forget to buy or carry condoms. The guys I’ve dated have always supplied them!* I tend to hang around with people from sex positive communities, and people really do take good condom use seriously. I wonder if there’s anyway to get non sex-positive people to take condom use as seriously.

          *The few times I have wanted to have sex and there have been no condoms, we have not had penetrative sex.

        • Sue Donym says:

          Source: The Real Problem with Male Condoms Is Nonuse. I actually doubt this study because the failure rate due to condoms slipping or breaking sounds too low relative to just not putting them on. Apparently people say they use condoms as primary birth control whether they actually bother to use them or not.

          It’s not very fair to say condoms are ineffective and easy to forget – almost all of the former comes from the latter. Thinking over contraception options and deciding to use condoms every time is already strong evidence that you’re not going to forget them, so you can’t expect a 15% failure rate on top of that.

    • amuchmoreexotic says:

      Not only are condoms a relatively ineffective and potentially enjoyment-lessening[1] method of contraception, what country do you live in where everybody has a guaranteed minimum-wage job? In my country, 1 in 4 under-25s (historically the sexiest demographic) is unemployed. At a conservative estimate, that’s a trillion sperm yearly that need to be contained.

      [1] at least for the penis-bearing sex participant – they might delay ejaculation and thus increase enjoyment for the penetree.

  4. Awesome work, and yet more support for my heuristic that when Catholics talk about biology or medicine, they describe a weird parallel version where a consequentialist would want to follow their deontological ethics. For example, it’s not enough for condoms to be ineffective, they have to have special channels in them permeable to HIV (but apparently not water).

    My favourite ever example of the weird parallel version of human biology is this, from a comment on Unequally Yoked:

    FYI, re: water in glass logic. This IMHO may still be a
    worthwhile approach to take in a biology class on human epigenetics and
    immunology (cells from every intimate contact course through human
    bodies for the rest of their days, females transfer them to their babies
    during gestation, siblings carry copies of riper fruits of the womb,
    IOW copies of genes from anyone who spent time in that vicinity other
    than their father). This is a burgeoning area in the epidemiology of
    poorly characterized chronic and fatal diseases (why childhood HPV
    vaccination is such a logical non-starter — “pretence of protection
    from a well-known disease-promoting agent to encourage you to expose
    yourself to untold risk of other diseases instead”?).

    It’s true that fetal cells survive in maternal circulation after pregnancy, but here this has been extrapolated to a world where if you have sex with more than one man, their sperms will loiter for the rest of your life, and their genes will get into your baby! Amazing stuff.

    You rarely hear “I admit [intervention X] will prevent [tragedy Y], but my deontology tells me its immoral”. It’s always something like “HPV vaccines are LOGICALLY IMPOSSIBLE”. It’s like Catholics are reverse consequentialists – they know what practices are morally bad, and it simply remains to invent some bad consequences.

    • Patrick (orthonormal) says:

      > It’s like Catholics are reverse consequentialists – they know what practices are morally bad, and it simply remains to invent some bad consequences.

      “Look out for reverse consequentialism” might be a great intuition pump for evaluating arguments that mix moral and practical factors…

      • Fnord says:

        Yeah, “reverse consequentialism” of that sort is definitely something a lot of people do, not just Catholics. Probably related to confirmation bias.

      • houseboatonstyx says:

        And, “Look out for bait and switch”. Anti-choicers use a lot of consequential material in their promotions — consequence to the fetus — building up an inductive case that abortion is wrong because of those consequences.

        But when consequence clearly calls for abortion — in the case of a fetus that cannot be saved, where the only choice is whether the mother dies too, leaving her other children orphaned — they come down hard with deontology “because abortion is wrong”.

        • Damien says:

          That seems to be more true of doctrinaire Catholics than of other abortion foes; my impression is that US Protestant opponents tend to be friendlier to “life of the mother” or even “rape and incest” exceptions, as well as to birth control as a concept.

    • Damien says:

      Almost everyone seems to be a stealth or backup consequentialist, believing their deontology or virtues are also practically justified. I first saw this with Milton Friedman. “I would support freedom even if it didn’t increase prosperity, which of course it does.” I was impressed at first, but I was like 14. At some point I noted it was a cheap thing to say if you do believe in the consequences.

      To be fair, I think Roderick Long has argued that most consequentialists are stealth deontologists as well, who’ll readily argue why some simple application of consequentialism doesn’t entail their supporting some moral catastrophe.

    • B_For_Bandana says:

      > You rarely hear “I admit [intervention X] will prevent [tragedy Y], but my deontology tells me its immoral”.

      No wonder, since all such arguers know that the barbarians outside their group don’t share their deontology. What alternative is there but to trick them into doing the right thing?

      • amuchmoreexotic says:

        Well, the existence of God can be known by the natural light of reason from created things – I know that’s true because it’s a Catholic dogma – you’d think it would be easier just to establish God’s existence and then go from there.

  5. Deiseach says:

    A completely unscientific and biased personal opinion on “how can contraception increase rates of abortion”.

    Ireland, as you may or may not be aware, is currently in the middle of a fight over legislation to permit abortion in limited circumstances. Now, this is partly down to the fact that we never permitted abortion under any circumstances to date, but even so, some of the pro-abortion campaigners are already stating that they won’t rest with “only in rape or incest”, they want abortion on demand (more or less). Yet we have contraception and family planning services in place, so why would we need abortion services? Ireland is a Modern European Country nowadays, we’ve put all that old Catholic guilt over having sex outside of marriage behind us, we’re free and independent and liberated and we can buy condoms in the supermarket just like the Brits, so what’s the problem?

    We’ve had available contraception for about thirty or so years. I’m old enough to remember all the propaganda (I told you this was a personally biased account) that if only we had access to various forms of contraception, this would magically do away with all unwanted/unplanned/accidental pregnancies. Yeah – that didn’t happen.

    (1) The only 100% guaranteed method not to get pregnant is not to have penetrative sex involving ejaculation between fertile partners
    (2) All forms of contraception have some rate of failure per thousands – the more people having sex, the more likely there are to be some failures
    (3) People don’t use it properly
    (4) People don’t use it at all (e.g. they get drunk out of their heads on the weekend, they shift someone, they end up having unprotected sex because they’re too hammered to think things through)
    (5) If you don’t want a child, your contraception fails, then you are going to want to avail of abortion if it is available
    (6) In conclusion, the more sex people are having and the more people are having sex, the more failures of contraception there are going to be, and the more demand for abortion there will then be.

    In other words, when it is socially acceptable to terminate unwanted pregnancies, when it is socially acceptable to be sexually active outside of and independent of marriage, and when there are always going to some rate of failure no matter what method you use (condoms alone – 1% rate allegedly from one site, which means 1 in 100 times having sex may result in pregnancy – do up the numbers for ‘hundreds of thousands of instances of sex’ and calculate possible unwanted pregnancy rates from that), then there is going to be the demand for abortion. Especially if the campaigns against teenage pregnancy revolve around “Get pregnant and your life is completely, irrevocably ruined because you will never get an education, never get a good job, never be able to achieve anything if you’re stuck with a baby when you’re a teenager”. Put on top of that “If you want to achieve anything in your career, for God’s sake don’t get pregnant until you’re within spitting distance of forty”, and then add in social pressure of “Everyone is having sex, there’s something wrong with you if you’re not having sex because if you can’t get a romantic partner you are a sad, miserable loser” – what do you expect to happen?

    • Damien says:

      As mentioned, contraception methods vary. A society that accepted sex and birth control while really wanting to bring down unwanted pregnancies would make IUDs free[1] along with lots of advertising about getting IUDs.

      [1] Or mandatory, per Bujold’s Beta Colony. (Which uses undescribed ‘implants’, could be IUD, hormonal, or some other physical barrier; pretty much perfectly effective and applied at menarche, along with anesthetized breaking of the hymen.)

    • anodognosic says:

      Failure rates are not calculated per instance of intercourse; they represent the chance of pregnancy per year.

    • g says:

      Would you care to give, say, two examples of people saying things that could halfway-reasonably even be caricatured as claiming that access to contraception would “magically do away with all unwanted/unplanned/accidental pregnancies”?

      Your 6-point argument explains how better access to contraception might not reduce abortion as much as one might naively think but that’s not the question at issue. Of course more sex, all else being equal, means more unwanted pregnancies; but also-of-course easier contraception, all else being equal, means fewer unwanted pregnancies; the question is how those actually trade off against one another.

      The section of Scott’s post headed “The anti-contraceptive position” makes the exact same argument you’re making here (minus some of the rhetoric) and also explains how it might be that the tradeoff ends up with an actual net increase in abortion.

  6. Damien says:

    Awesome research, Scott!

    • Paul Torek says:

      +1. Also, Scott, is there any way you can transition from general psychiatry to something more epidemiology-focused? Just a suggestion – you have some awesome talents, and the world could benefit mightily from them.

    • Scott Alexander says:


      Paul, I’m good at the kind of epidemiology that involves asking Google what other people have figured out, and less good at the kind that involves doing my own research.

  7. Douglas Knight says:

    The question of whether abortion is legal is very difficult. The Spanish abortion rate only increased 5% in 2010 when it introduced abortion on demand (smaller than 9/10 annual changes 1997-2007). This suggests that it was already de facto legal in 2007. Perhaps the change in usage 1997-2007 is due to such de facto legal change. Or perhaps not, since by 1997 the Spanish had stopped travelling abroad to get abortions. The 1997 Spanish abortion rate was lower than the contemporary Irish abortion rate, despite the Irish women needing to travel to Great Britain. Perhaps they needed to travel within Spain to find a cooperative clinic, just not the France, but by 2007 all the clinics were cooperative.

  8. suntzuanime says:

    What is it that leads you to classify 19-year-olds having children as a “social problem”? Isn’t the social problem really things like demographic collapse and increased risk of birth defects due to people deferring childbirth until their thirties and forties if at all?

    • Scott Alexander says:

      There are probably societies where 19 year olds having children would be great, but ours contingently isn’t one of them.

  9. naath says:

    The argument that “contraception –> belief that sex != babies –> more sex –> more unwanted pregnancies” is a compelling one. However I think it is entirely wrong to assume that pre legalised, medically proven contraception people were not attempting to prevent or abort unwanted pregnancies. Records of contraceptive and abortion inducing practices date back almost as far as records exist at all (many of them don’t work, are very dangerous, or both) and of course records of people abandoning or killing unwanted infants do too.

    I would argue that the belief that having sex does not need to lead to *raising a child* is a very old one. We’ve just improved the technology involved.

  10. Ben L says:

    Typo, 6th paragraph: “But the rest of it is that it’s ***jsut*** this really elegant and unexpected finding”

  11. Withheld says:

    Thank you for this fantastic analysis. It makes me so very glad that this exists.

    I work in research at Guttmacher and just wanted to clarify a couple of things. First, as much as we’d love to take credit for the article you cite, Relationships Between Contraception and Abortion: A Review of the Evidence, it’s not actually Guttmacher work. It was published in our peer-reviewed journal (which is why you can access it on the site) but the study was conducted and written up by unaffiliated researchers.

    Second, external sources in that article are cited diligently but are not linked because for the most part they are books or restricted-access journal articles. Aside from the fact that PDF linking hadn’t exactly reached its zenith by 2003, links to these sources either don’t exist or would be useless to lay readers. Mainly though, there aren’t external links because the empirical claims in the article are based on analyses conducted by the authors using data from the countries. The tables and figures in the article are the original sources.

    Thank you so much for writing this, for thinking about this, and for using our website and journal exactly how they’re meant to be used! I really, really enjoyed this post.

    • Scott Alexander says:

      Thank you very much!

      Hey, if you work at Guttmacher, can you answer a question for me?

      I recently read this critique of you guys. I was able to find your paper on how Koch’s sampling procedure is worse than your own, and it makes sense, but I didn’t find a good rebuttal to the main claim that your methodology overestimated the number of abortions in the Mexican federal district by 10x, except one claim that there are probably illegal abortions still going on (but it seems hard for there to be 10x as many of them) and another saying Koch confused your Mexico City estimate with your all of Mexico estimate (which he did, once, but that estimate was off by 100x and even the correct Mexico City estimate seems to be off by 10x). Do you have a more complete response somewhere?

  12. Pingback: Getting a Little More Detailed with the Contraception/Abortion Connection

  13. Pingback: The Contraception/Abortion Connection: Part Two

  14. Pingback: A few graphs about teen pregnancy and sex | Alas, a Blog