 Hi, I'm Salvatore Bobonas, and today's lecture is on skewed sex ratios at birth. Biologically, in human beings, an average of around 105 boys are born for every 100 girls. This seems to be a nature's way of adjusting for the fact that boys simply don't seem to be as robust as girls. More boys die in infancy than girls. They're more susceptible to disease than girls are. And of course, in adolescence, many more boys die in accidents than girls do. As a result, by planning more boys than girls at birth, nature assures that in the natural course of events, there will be roughly the same number of boys and girls of reproductive age. Now, historically, female infanticide, the killing of girl babies, was common in many countries, leading to skewed sex ratios that favored boys. But today that's virtually disappeared. Today, skewed sex ratios have returned, but not due to infanticide, primarily it's now due to sex-selective abortion and sex-selective artificial insemination. Biological reproduction, as I said, produces a sex ratio of around 105 boys per girl at birth. We usually express the sex ratio as number of boys per 100 girls, just to give it a convenient number. But sometimes it's also reported as a simple ratio, so for example 1.05 boys per girls. Very occasionally you'll see it flipped the other way as the number of girls per 1,000 boys. In that case, you could think of it as the girl deficit, but that makes it a little bit confusing because the natural number of girls per 1,000 boys is 952, which means that anything less than 952 represents a deficit of girls, and that can be a bit hard to remember as a number. Until the late 1980s, the global sex ratio hovered around just under 1.06. It was like 105.5, 105.7, reflecting a residual level of female infanticide in some places, like very poor and rural areas of India and Pakistan, and some very poor rural areas of sub-Saharan Africa. But since the 1990s, the global sex ratio has risen to over 107, driven mainly by super high sex ratios at birth in India and China. The numbers I give there, 111 for India, 115 for China are the official World Bank figures for those countries for the year 2015. In fact, both countries are probably a little bit higher than those numbers suggest. If you look at the map, and this again is official World Bank data for 2015, you'll see that high sex ratios are overwhelmingly concentrated in South and East Asia. The countries affected today are primarily India, Pakistan, China, and Vietnam. There are a small number of cases of warped sex ratios in the rest of the world, for example in Azerbaijan, but really in terms of pure numbers, because India and China each have nearly 1.4 billion people. The warped sex ratios in those countries are responsible for most of the global excess of boys. Now in some countries, and under some circumstances, some preference can produce truly staggering sex ratios. So this table shows some data for sex ratios in China and South Korea by parity, that is by birth order, for a woman's first birth, second birth, or fourth birth. If you look at South Korea in around 1990, 1989 to 1992, and you look at the sex ratio for third and fourth births, they were approaching 200. That means that on average, for women who had multiple children in South Korea, that third or fourth child was twice as likely to be a boy as a girl. Now that number has since come down, it's still high, but it's since come down as a result of government education campaigns, trying to persuade people not to practice sex-selective abortion. Sex-selective abortion became possible only in the late 1980s with ultrasound technology, and here you see it impacting South Korea just at that point. ultrasound technology came a little later to China, though again, you'll see sex ratios starting to rise in the late 1980s. It's really the massive wave of sex-selective abortion hit China closer to the year 2000. Society-wide sex ratios are almost always skewed to the overproduction of boys, though individuals of course can use the same tool to have girls if they want. Among poorer households and in poorer countries, the main mechanism is sex-selective abortion via ultrasound technology. Ultrasound has become very widely disseminated throughout the world, and it can be used to abort children who can be viewed on the ultrasound as being girls. Among richer households and in richer countries, this is much less common. In richer countries, the reason for warped sex ratios is now tilting towards selective fertilization. When I say richer countries, I even mean the richer areas of China, where if people are only having one child now under the two-child policy, they may be having a second child, but still they might be very careful about choosing what child they want, and they may do it at later and later ages, and maybe moving towards in vitro fertilization, which is becoming more and more common. And thus they're choosing to implant only those eggs that can be identified genetically as being male eggs. Boys are often preferred for economic or cultural reasons. I think this has to be stressed that go beyond simple personal prejudice or desire for a baby of a particular sex. It's very easy to condemn sex-selective abortion or sex-selective fertilization, because the overall consequences are so dramatic, producing these massive deficits of girls, massive overabundance of boys around the world, especially in China and India. But we have to keep in mind that for poor families, the need to have a boy to labor on a farm may be the difference between eating and not eating, you know, if the girl is unable to do the heavy labor required on the farm. Similarly, in strongly patrilineal societies where the family name goes with the boy, it may be considered simply essential to have at least one boy. Now that's something that I personally don't endorse and that many people listening to this lecture won't endorse. But if you live in a society where you believe that the shrine of the family gods can only be maintained by a male heir, well, not having a boy is akin to allowing all the past generations of the family to perish. That can be a very powerful motive for people to want to have a son. And finally, you know, in societies that don't have adequate systems of social security and elderly old age support, if it's perceived that boys will have higher incomes and in most countries, actually in all countries, men do earn higher income for the same work as women and men work at higher rates than women. So if you put that together, male income dramatically surpasses women's income around the world and as a result, it can be a very rational response of parents that they want a boy to support them in old age. I would say it can be a rational response because there's a lot of evidence that even though the boys are richer, they don't support their parents as much as the girls do. But that aside, parents may want their children to make more money and if we know that boys make more money than girls, on average, then there might be a strong reason, especially in poor countries, for parents to choose to have boys. Look, this technology is coming to be every day available to middle class parents in all rich and middle income countries. We can now produce designer babies and the only limit on that are poorly enforced regulatory restrictions. So right now, if you want to choose whether to have a boy or a girl or even if you want to choose the eye color of your baby, if you want a blue eye baby, a green eye baby, a brown eye baby, you can do that through selective choice of fertilized eggs for in vitro fertilization. And it only costs $10,000, $20,000 to get it done. It's illegal in Australia, but it's perfectly legal in the United States, Mexico, Thailand, and many Australian mothers simply fly to Thailand to have the procedure performed. In fact, people in countries like Australia where it's illegal can simply go to an Australian-owned and managed clinic in Thailand and have the in vitro fertilization done there in order to choose the sex of their baby. If they don't trust Thailand and if they have a little more money, they can go to the United States. In the United States, it's perfectly legal to choose the sex of your child or even the eye color of your child via in vitro fertilization. Even the regulatory restrictions in place on that tend to have a lot of loopholes. So for instance, in China, it is illegal to choose the sex of your baby, but illegal, but nonetheless very commonly practiced. In Australia, it is not commonly practiced. It's considered unethical and it's, I believe also illegal in Australia to choose to select the sex of a baby via IVF unless the health of the mother is endangered by having a baby of a particular gender. And right now in Australia, there is a movement to classify gender disappointment as a psychological illness that could then justify the selection of the sex of the baby. So very soon, all countries are going to have to grapple with this question. Whatever the society-wide sex ratio, the fact is that we have to grapple with the individual moral question of should parents be allowed to choose? We have the technology to choose. People are going to use the technology unless there's very strong regulation and education to prevent it. Okay, key takeaways. First, sex ratios of birth are usually expressed as a number of boys per 100 girls with a natural ratio being around 105. Second, sex selective abortion and selective fertilization are respectively the low cost and the high cost forms of sex selection. And third, designer babies have simply become a reality for which society has not developed appropriate ethical principles. Thanks for listening. I'm Salvatore Bobonis. You can find out more about me at my website, salvatorebobonis.com, where you can also sign up to get my monthly Global Asia newsletter.